103 results on '"Machining centers"'
Search Results
2. Modeling the Work of Multi-spindle Machining Centers with the Petri Nets Roman STRYCZEK.
- Author
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STRYCZEK, Roman
- Subjects
- *
PETRI nets , *EVIDENCE gaps , *TECHNICAL literature , *MACHINERY , *BUSINESS hours - Abstract
The article presents the results of the simulation studies concerning the impact of random production interruptions on the efficiency of multi-spindle machining centers. Four different machining center configuration models were developed using a dedicated class of stochastic Petri nets. In addition to the number of machine spindles, the number of simultaneously mounted parts, loading time of parts, their machining time, and reliability parameters regarding the frequency of machine interruptions caused by random factors were also taken into account as model parameters. A series of virtual tests was carried out for machining processes over a period of 1000 hours of operation. Analysis of the results confirmed the purpose of conducting simulation tests prior to making a decision regarding the purchase of a multispindle milling center. This work fills the existing research gap, as there are no examples in the technical literature of evaluating the effectiveness of multi-spindle machining centers. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
3. Production of Protective Face Shields in Cincinnati, Ohio, USA from the 1819 Innovation Hub at the University of Cincinnati
- Author
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Doehler, Steven, Jones, Benjamin S., and Rybicki, Frank J., editor
- Published
- 2021
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4. Mapping positional accuracy for milling machine table
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D. A. Blokhin, Yu. A. Blokhina, and M. M. Lakman
- Subjects
machining centers ,processing accuracy ,rigidity of the machine tool system ,vibration resistance ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
The article presents a technique for compiling a map of the positional accuracy of the table of a vertical milling machine when a vibration load of various frequencies is applied. A laboratory setup for creating forced oscillations of a cross table has been developed and manufactured. The reasons for the emergence of the highest deviations in specific areas of the working area of the machine tool are analyzed.
- Published
- 2021
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5. Study of energy consumption in Haas UMC-750 and Leadwell V-40iT® CNC machining centers.
- Author
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Ardila, María I., Rudas, Juan. S., Núñez, Edwin J., Rodríguez, Miguel A., Ardila, Juan G., Cardona Jiménez, Johnatan, and Isaza, Cesar
- Subjects
- *
ENERGY consumption , *NUMERICAL control of machine tools , *SURFACE roughness , *SURFACE finishing , *CUTTING tools , *FACTORIAL experiment designs , *CUTTING machines , *SPINDLES (Machine tools) - Abstract
Machining centers are complex equipment that demand high energy consumption affecting the production costs. Different studies have related some factors with the energy consumption; however, it is not completely clear which variables or factors have a greater incidence in this energy consumption of these machining centers without decreasing the quality of the finishing surfaces of the manufactured parts. In the present study, an analysis of the influence of cutting depth, forward velocity and spindle speed on the energy consumption and roughness of the surface finish was carried out in the Haas UMC-750 and the Leadwell V-40iT® machining centers. An experiment was developed with an nK factorial design keeping some variables as constants such as the base material, the cutting tool and the machining path. The results obtained showed that by increasing the feed rate, energy consumption can decrease by up to 50% for the machining centers studied without influencing the surface quality. Besides, the interaction between the factors was evidenced, identifying that the cutting depth has a moderate influence on the roughness or surface finish of the manufactured parts. The energy consumption varies for each machining center and the experimental design developed helped to characterize the influence of some cutting variables on the energy consumption of each machining center. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
6. Multi-objective optimization of machining parameter in laser drilling of glass microballoon/epoxy syntactic foams
- Abstract
The effect of CO2 laser drilling on glass microballoon/epoxy syntactic foams are investigated in this study to optimize machining parameters to achieve a clean hole for various industrial applications. The epoxy matrix is reinforced with glass microballoons in concentrations of 0, 20 and 40 vol%. Cutting speed, laser power and additive percentage are input parameters for optimization. Kerf taper angle, surface roughness and ovality percentage are used as output responses to evaluate hole quality. For the optimization study, hybrid multi-criteria decision-making methods such as grey relational analysis and multi-objective optimization with ratio assessment methods are used, with equal weightage given to each output response. According to the study, low power and high speed produce better machining results such as a smaller kerf taper angle, lower surface roughness and a lower ovality percentage. Furthermore, a higher additive percentage is not appropriate for laser in epoxy/glass microballoon composite because it burns the area near the laser and increases surface roughness. © 2023 The Author(s)
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- 2023
- Full Text
- View/download PDF
7. Multi-objective optimization of machining parameter in laser drilling of glass microballoon/epoxy syntactic foams
- Abstract
The effect of CO2 laser drilling on glass microballoon/epoxy syntactic foams are investigated in this study to optimize machining parameters to achieve a clean hole for various industrial applications. The epoxy matrix is reinforced with glass microballoons in concentrations of 0, 20 and 40 vol%. Cutting speed, laser power and additive percentage are input parameters for optimization. Kerf taper angle, surface roughness and ovality percentage are used as output responses to evaluate hole quality. For the optimization study, hybrid multi-criteria decision-making methods such as grey relational analysis and multi-objective optimization with ratio assessment methods are used, with equal weightage given to each output response. According to the study, low power and high speed produce better machining results such as a smaller kerf taper angle, lower surface roughness and a lower ovality percentage. Furthermore, a higher additive percentage is not appropriate for laser in epoxy/glass microballoon composite because it burns the area near the laser and increases surface roughness. © 2023 The Author(s)
- Published
- 2023
- Full Text
- View/download PDF
8. Multi-objective optimization of machining parameter in laser drilling of glass microballoon/epoxy syntactic foams
- Abstract
The effect of CO2 laser drilling on glass microballoon/epoxy syntactic foams are investigated in this study to optimize machining parameters to achieve a clean hole for various industrial applications. The epoxy matrix is reinforced with glass microballoons in concentrations of 0, 20 and 40 vol%. Cutting speed, laser power and additive percentage are input parameters for optimization. Kerf taper angle, surface roughness and ovality percentage are used as output responses to evaluate hole quality. For the optimization study, hybrid multi-criteria decision-making methods such as grey relational analysis and multi-objective optimization with ratio assessment methods are used, with equal weightage given to each output response. According to the study, low power and high speed produce better machining results such as a smaller kerf taper angle, lower surface roughness and a lower ovality percentage. Furthermore, a higher additive percentage is not appropriate for laser in epoxy/glass microballoon composite because it burns the area near the laser and increases surface roughness. © 2023 The Author(s)
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- 2023
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- View/download PDF
9. A data-driven method based on deep belief networks for backlash error prediction in machining centers.
- Author
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Li, Zhe, Wang, Yi, and Wang, Kesheng
- Subjects
FORECASTING ,BOLTZMANN machine ,SUPPORT vector machines ,MECHANICAL wear ,BACK propagation ,PROGNOSIS - Abstract
Backlash error occurs in a machining center may lead to a series of changes in the geometry of the components and subsequently deteriorate the overall performance of the equipment. Due to the uncertainty of mechanical wear between kinematic pairs, it is challenging to predict backlash error through physical models directly. An alternative method is to leverage data-driven models to map the degradation. This paper proposes a data-driven method for backlash error predication through Deep Belief Network (DBN). The proposed method focuses on the assessment of both current and future geometric errors for backlash error prediction and subsequent maintenance in machining centers. During the process of prognosis, a DBN via stacking Restricted Boltzmann Machines is constructed for backlash error prediction. Energy-based models enable DBN to mine information hidden behind highly coupled inputs, which makes DBN a feasible method for fault diagnosis and prognosis when the target condition is beyond the historical data. In the experiment, to confirm the effectiveness of deep learning for backlash error prediction, similar popular regression methods, including Support Vector Machine Regression and Back Propagation Neural Network, are employed to present a comprehensive comparison in both diagnosis and prognosis. The experimental results show that the performances of all these regression methods are acceptable in the diagnostic stage. In the prognostic stage, DBN demonstrates its superiority and significantly outperforms the other models for backlash error prediction in machining centers. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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10. Multi-objective optimization of machining parameter in laser drilling of glass microballoon/epoxy syntactic foams
- Author
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Shweta Singh, Mrityunjay Doddamani, and Satvasheel Powar
- Subjects
Multicriterion decision makings ,Glass microballoons ,Kerf taper ,Glass microballoon ,Biomaterials ,Carbon dioxide lasers ,Multicriteria decision-making ,Multi-criteria decision making ,Surface roughness ,Machining centers ,Multi criteria decision-making ,Energy Systems ,Multi-objectives optimization ,Multiobjective optimization ,Energisystem ,Floors ,Syntactic foams ,Laser drilling ,Machining parameters ,Metals and Alloys ,Additives ,Infill drilling ,Quality control ,Foams ,Surfaces, Coatings and Films ,Epoxy ,Ceramics and Composites ,Glass ,Syntactics ,Syntactic foam ,Decision making - Abstract
The effect of CO2 laser drilling on glass microballoon/epoxy syntactic foams are investigated in this study to optimize machining parameters to achieve a clean hole for various industrial applications. The epoxy matrix is reinforced with glass microballoons in concentrations of 0, 20 and 40 vol%. Cutting speed, laser power and additive percentage are input parameters for optimization. Kerf taper angle, surface roughness and ovality percentage are used as output responses to evaluate hole quality. For the optimization study, hybrid multi-criteria decision-making methods such as grey relational analysis and multi-objective optimization with ratio assessment methods are used, with equal weightage given to each output response. According to the study, low power and high speed produce better machining results such as a smaller kerf taper angle, lower surface roughness and a lower ovality percentage. Furthermore, a higher additive percentage is not appropriate for laser in epoxy/glass microballoon composite because it burns the area near the laser and increases surface roughness. © 2023 The Author(s)
- Published
- 2023
11. A General Empirical Energy Consumption Model for Computer Numerical Control Milling Machine.
- Author
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Yadan Zeng, Tonghui Li, Yelin Deng, and Chris Yuan
- Subjects
- *
ENERGY consumption , *NUMERICAL control of machine tools , *MILLING-machines - Abstract
Energy consumption of computer numerical control (CNC) machines is significant and various empirical models have been developed to model the specific energy consumption (SEC) of CNC machines. However, most of the models are developed for specific machines and hence have limited applications in manufacturing industry. In this research, a general empirical SEC model for milling machine at certain power level is developed based on actual cutting experimental data. In this model, stand-by power and spindle power are used in the SEC model for the first time. The material removal rate (MRR) is used to represent the cutting parameter. The proposed model is fitted by the regression analysis and validated using experimental data. Results show that the proposed model can be applied on various milling machines with an average absolute residual ratio of 6%. The model is also validated through a series of cutting experiments on a machine center, with an accuracy of 91.5%, for the SEC calculation. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
12. Estudio de consumos energéticos en los centros de mecanizado CNC Haas UMC-750 y Leadwell V-40iT®.
- Abstract
Machining centers are complex equipments that demand high energy consumption affecting the production costs. Different studies have related some factors with the energy consumption, however it is not completely clear which variables or factors have a greater incidence in this energy consumption of these machining centers without decreasing the quality of the finishing surfaces of the manufactured parts. In the present study, an analysis of the influence of cutting depth, forward velocity and spindle speed on the energy consumption and roughness of the surface finish was carried out in the Haas UMC-750 and the Leadwell V-40iT® machining centers. An experiment was developed with an nK factorial design keeping some variables as constants such as the base material, the cutting tool and the machining path. With the results obtained, it was possible to identify that the forward velocity is the factor that depends the most on energy consumption. Besides, the interaction between the factors was evidenced, identifying that the cutting depth has a moderate influence on the roughness or surface finish of the manufactured parts. The energy consumption varies for each machining center and the experimental design developed helped to characterize the influence of some cutting variables on the energy consumption of each machining center., Los centros de mecanizado demandan un alto consumo de energía afectando los costos de producción en las empresas que los emplean. Diferentes estudios relacionan múltiples factores de los centros de mecanizado con el consumo de energía, pero hasta el momento no se identifica con claridad cuáles variables o factores tienen una mayor incidencia en el consumo de energía sin disminuir la calidad del acabado superficial de las piezas fabricadas. En el presente estudio se realizó un análisis descriptivo de la influencia que tiene la profundidad de corte, la velocidad de avance y la velocidad del husillo sobre el consumo de energía y la rugosidad en los centros de mecanizado Haas UMC-750 y el centro Leadwell V-40iT®. Se desarrolló una experimentación con un diseño factorial tomando como factores fijos el material base, la herramienta de corte y la ruta de mecanizado. A partir de un análisis descriptivo de los resultados obtenidos en este experimento se logró identificar que la velocidad de avance es el factor que más relación tiene con el consumo de energía. Además, se evidenció la interacción entre los factores identificando que la profundidad de corte posee una influencia moderada sobre la rugosidad o acabado superficial de las piezas. El consumo de energía varía para cada centro de mecanizado y el diseño experimental desarrollado ayudó a caracterizar la influencia de algunas variables de corte sobre el consumo de energía en cada centro de mecanizado.
- Published
- 2022
13. Energy Consumption of Feed Drive Systems Based on Workpiece Setting Position in Five-Axis Machining Center.
- Author
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Ryuta Sato, Keiichi Shirase, and Akio Hayashi
- Subjects
- *
ENERGY consumption , *NUMERICAL control of machine tools - Abstract
Energy consumption of numerical control (NC) machine tools is one of the key issues in modern industrial field. This study focuses on reducing the energy consumed by a five-axis machining center by changing only the workpiece setting position. Previous studies show that the movements along each axis in five-axis machining centers depend on the workpiece setting position, regardless of whether the same operation is performed. In addition, the energy consumptions required for the movements are different along each axis. From these considerations, an optimum workpiece setting position that can minimize the energy consumed during these motions is assumed to exist. To verify this assumption, in this study, the energy consumed by the feed drive systems of an actual five-axis machining center is first measured and then estimated using the proposed model in this study. The model for estimating the energy consumption comprises the friction, motor, and amplifier losses along each axis. The total energy consumption can be estimated by adding the energy consumptions along each axis. The effect of the workpiece setting position on the energy consumption is investigated by employing the cone-frustum cutting motion with simultaneous five-axis motions. The energy consumption that depends on the workpiece setting position is first measured and then estimated. The results confirm that the proposed model can estimate the energy consumption accurately. Moreover, the energy consumption is confirmed to depend on the workpiece setting position; the minimum energy consumption is found to be 20% lower than the maximum one. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
14. FEM Analysis in a Machining Center
- Author
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Pavan, R., Tellan, M., Ruffati, V., Velarde, Manuel Garcia, editor, Sayir, Mahir, editor, Schneider, Wilhelm, editor, Schrefler, Bernhard, editor, Bianchi, Giovanni, editor, Tasso, Carlo, editor, and Kulianic, Elso, editor
- Published
- 2002
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- View/download PDF
15. Machining centers in the production of medical implants
- Author
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Botković, Ana and Ciglar, Damir
- Subjects
proizvodni proces ,implant ,implantat ,TEHNIČKE ZNANOSTI. Strojarstvo. Proizvodno strojarstvo ,production process ,obradni centri, implantat, proizvodni proces ,Obradni centri ,TECHNICAL SCIENCES. Mechanical Engineering. Production Mechanical Engineering ,Machining centers - Abstract
Ovaj završni rad bavi se tematikom obradnih centra u proizvodnji medicinskih implantata. U uvodnom dijelu navedeni su suvremeni zahtjevi tržišta i proizvodnje, prikazana je podjela obradnih strojeva s obzirom na tehnološki prostor te su navedene glavne karakteristike medicinskih implantata. U nastavku je dan opis obradnih centara, njihov povijesni razvoj, glavne značajke i prikazani su osnovni moduli obradnih centara. Detaljno su opisani tokarski obradni centar Tornos EvoDECO 16 i glodaći obradni centar HAAS VF-2SSYT u vlasništvu tvrtke Eonex d.o.o. koja se bavi proizvodnjom medicinskih implantata na obradnim centrima. U završnom dijelu rada, opisan je cjeloviti proizvodni proces izrade odabranog implantata, od samog dolaska sirovca u skladište, strojne obrade, završne obrade i kontrole, do pakiranja i isporuke gotovog proizvoda. This bachelor thesis delas with machining centers in the production of medical implants. In the introduction, the modern requirements of the market and production are listed, and the division of machine tools with respect to the technological space and the main characteristics of medical implants are shown. In further parts, a description of machining centers, their historical development, main features and basic modules of machining centers are given. Tornos EvoDECO 16 turning machining center and HAAS VF-2SSYT milling machining center owned by Eonex d.o.o., a company that produces medical implants on machining centers, are described in detail. In the final part of the paper, the complete production process of implant production is described, from the arrival of the raw material in the warehouse, machining, finishing and control, to packaging and delivery of the finished product.
- Published
- 2022
16. A review on drilling of FML stacks with conventional and unconventional processing methods under different conditions
- Author
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Doğan, Mehmet Akif, Yazman, Şakir, Gemi, Lokman, Yıldız, Murat, Yapıcı, Ahmet, Mühendislik ve Doğa Bilimleri Fakültesi -- Makina Mühendisliği Bölümü, Doğan, Mehmet Akif, Yıldız, Murat, and Yapıcı, Ahmet
- Subjects
In-fiber ,Machinability ,Engineering & Materials Science - Manufacturing - Tool Wear ,Process parameters ,Carbon Fiber Reinforced Plastics ,Materials Science ,GFRP composite pipes ,Drilling ,Fiber metal laminates (FML) ,Processing ,Mechanics ,Fiber metal laminate ,Cutting Force ,Delamination-free ,Surface roughness ,GFRP ,Machining centers ,CFRP ,Machining methods ,Tool wear ,Condition ,CFRP/TI6AL4V stacks ,Infill drilling ,Laminate stacks ,Thrust force ,Hole quality ,Machining ,Surface integrity ,Fibers ,Carbon-fiber ,Delamination ,Titanium-alloy ,Fiber-reinforced-plastics ,Fibre metal laminates - Abstract
Fiber and metal materials used in Fiber Metal Laminate (FML) have different machinability properties due to their different structures. This case has made it a research topic to obtain good hole quality in these materials. A good match between the parameters used is required for the machinability of FML. Traditional and non-traditional machining methods in the machining of FML in this article were investigated and a comprehensive review regarding the machining parameters and hole quality were conducted. Considering the methods and parameters used, the defects occurring in the holes (delamination, hole size and circularity, surface roughness, etc.) were determined and the most suitable processing methods and parameters were picked in order to minimize these defects. As a result, the most suitable machining method and optimum cutting parameters for a better hole quality in FML machinability are determined, and it is aimed that this study will be beneficial to scientific and industrial societies.
- Published
- 2022
17. Optimization of Planar Honing Process for Surface Finish of Machine Tool Sliding Guideways.
- Author
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Kory Chang and Masakazu Soshi
- Subjects
- *
HONING , *TOOLS - Abstract
Sliding guideways are often used as the foundation for linear motion in computer numerical control (CNC) machine tools due to their high damping capabilities especially for heavy duty machining applications. However, the traditional manufacturing process with grinding is time-consuming, and the product's sliding performance has not been optimized nor clearly understood. In order to increase productivity, a machining center based manufacturing method with cubic boron nitride (CBN) milling tools was introduced and tested by researchers. While greatly reducing manufacturing time and cost, a rougher milled surface, in comparison to traditional grinding, is a possible concern for the performance as well as the life of sliding guideways. In this study, a novel planar honing process was proposed as a postprocess of CBN milling to create a finish surface on hardened cast iron sliding guideways used for CNC machine tools. A design of experiment (DOE) was conducted to statistically understand significant factors in the machining process and their relationship with surface topography. Effective planar honing conditions were discovered and analyzed with three-dimensional (3D) and two-dimensional surface parameters. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
18. Part Quality Prediction in Multistage Machining Processes with Fixtures Based on Locating Surfaces Using Dual Quaternions
- Abstract
The mathematical modelling of variation propagation in multistage machining processes helps to perform a quick analysis and diagnosis of the processes. The models for part quality prediction, such as Stream of Variation, include homogeneous transformations of the vectorial representations of parts and fixtures. However, these prediction models are complex when considering fixtures with locating surfaces and the associated matrix size is large. Towards mitigating the mathematical complexity, dual quaternions are proposed in representing and transforming a virtual part and fixture. To achieve this, the primary feature datum is assembled to the primary locating surface, followed by sliding the part to secondary and tertiary locating surfaces by reducing the distance between the vertices of the part and the locating surface. The prediction following the proposed approach gave a result within 0.36 % of the prediction made using CAD/CAM models and maintained the largest matrix size of 9 by 8 for a part with 9 features., QC 20220913
- Published
- 2021
- Full Text
- View/download PDF
19. Informed machine learning-based machining parameter planning for aircraft structural parts
- Abstract
Aircraft structural parts are important and high-value parts used to constitute the frame of the aircraft, and are usually produced by NC machining, where the machining parameters are significant for the machining quality, efficiency, and cost. In the process planning, there are hundreds or even thousands of machining operations that require separate machining parameters, which is a huge task for the existing optimization-based methods that rely on iterative optimizations. Due to the complex structures and high requirements, the existing expert system-based methods require plenty of additional modifications. Recently, with the development of artificial intelligence, data-driven methods are used in machining parameter planning, which mines the knowledge and rules hidden in the historical data. However, the existing data-driven models require a large amount of training data and lack interpretability. To address this issue, this paper proposes an informed machine learning method for machining parameter planning, which introduces multiple prior constraints into the data-driven model. First, the part model is represented as an attribute graph, and the cutting area of each machining operation is correlated to a subgraph, which is used to obtain the vectorized representation of machining operation that covers cutting area and process information. Then, by fitting the mapping between the vectorized machining operation and the machining parameters, the knowledge and rules are learned. Next, to introduce prior constraints into the data-driven model, the constraint loss is designed and incorporated into the original loss function. The proposed method can generate machining parameters for all the machining operations in batch, thereby greatly reducing the human interactions. In the case study, the historical processing files of aircraft structural parts are used to train the proposed model for planning cutting width, cutting depth, spindle speed, and machining feedrate. The res, QC 20220825
- Published
- 2021
- Full Text
- View/download PDF
20. Surface topography after deep rolling with milling kinematics
- Abstract
Deep rolling is a machining process which is used to decrease roughness and to induce compressive residual stresses into component surfaces. A recent publication of this research group showed possibilities to predict the topography during deep rolling of bars in a lathe. Although deep rolling can be used in a milling machine to machine flat specimens, it is still unclear, whether the topography can be predicted to a similar extend using this application. To investigate the influence of the machining parameters on topography, three experimental stages are performed in this paper on cast AlSi10Mg. First, single-track deep rolling experiments are performed under variation of the deep rolling pressure pw to find the relationship between pw and the indentation geometry. Here, a logarithmic relationship between deep rolling pressure and the indentation characteristics could be found that achieved a relatively high agreement. In the second stage, surfaces are prepared using multi-track deep rolling. Here, the deep rolling pressure pw and the lateral displacement ab are varied. The multi-track rolled surfaces were compared to an analytical model for the calculation of the theoretical roughness that is based on the logarithmic relationship found in the first experimental stage. Here, the limits of the analytical prediction were shown because high similarities between predicted and measured surfaces only occurred for certain deep rolling pressures pw and lateral displacements ab. To further investigate the limitations of this procedure, a novel tool concept, which utilizes the rotation of the machine spindle, is used in the third stage. Here, the generated surface can also be interpreted as a periodic sequence of spheric indentations as shown in the second experimental stage, whereas the measured surfaces differed from the expected surfaces. As a result of this paper, the predictability of the surface topography after deep rolling of flat specimens is known (minimum pressure
- Published
- 2021
21. Surface topography after deep rolling with milling kinematics
- Abstract
Deep rolling is a machining process which is used to decrease roughness and to induce compressive residual stresses into component surfaces. A recent publication of this research group showed possibilities to predict the topography during deep rolling of bars in a lathe. Although deep rolling can be used in a milling machine to machine flat specimens, it is still unclear, whether the topography can be predicted to a similar extend using this application. To investigate the influence of the machining parameters on topography, three experimental stages are performed in this paper on cast AlSi10Mg. First, single-track deep rolling experiments are performed under variation of the deep rolling pressure pw to find the relationship between pw and the indentation geometry. Here, a logarithmic relationship between deep rolling pressure and the indentation characteristics could be found that achieved a relatively high agreement. In the second stage, surfaces are prepared using multi-track deep rolling. Here, the deep rolling pressure pw and the lateral displacement ab are varied. The multi-track rolled surfaces were compared to an analytical model for the calculation of the theoretical roughness that is based on the logarithmic relationship found in the first experimental stage. Here, the limits of the analytical prediction were shown because high similarities between predicted and measured surfaces only occurred for certain deep rolling pressures pw and lateral displacements ab. To further investigate the limitations of this procedure, a novel tool concept, which utilizes the rotation of the machine spindle, is used in the third stage. Here, the generated surface can also be interpreted as a periodic sequence of spheric indentations as shown in the second experimental stage, whereas the measured surfaces differed from the expected surfaces. As a result of this paper, the predictability of the surface topography after deep rolling of flat specimens is known (minimum pressure
- Published
- 2021
22. A modular node-based modeling platform for the simulation of machining processes
- Abstract
Increasing precision requirements motivate research on the system perspective of machining systems. Virtual environments for the prediction of the Process Machine Interaction (PMI) are one key to obtain a priori understanding of machining accuracy, save expensive testing and planning time of industrial users, and increase the overall resource utilization. This paper introduces the modular node-based software platform SharpCut (#cut). The platform follows a sequential modeling approach of manufacturing processes and machine tools by using nodes. The novelty of the method lies in its open architecture with a strong focus on extendibility, adaptability, and research applicability. Besides the node-based modeling approach, four implemented software modules are described. The four modules are the workpiece discretization, the tool and cutting inserts, the material removal, and the system's kinematics. The machine tool's motion and kinematic errors are modeled with Homogeneous Transformation Matrices (HTMs). The workpiece discretization is performed with a memory-efficient implementation of Depth Elements (Dexels). The material removal follows from the modelling of the Tool-Workpiece Engagement (TWE) with a generic model of the tool and the computationally efficient MÖLLER-TRUMBORE ray-triangle intersection algorithm. With the presented modules, it is possible to predict the results of machining processes and perform sensitivity or root cause analyses. The paper concludes with an example model and simulation of a face-milling process., Part of proceedings ISBN: 978-0-9957751-9-0QC 20220330
- Published
- 2021
23. Modelling 3D metal cutting problems with the particle finite element method
- Abstract
This work presents the development of the Particle Finite Element Method (PFEM) for the modelling of 3D solid mechanics problems under cutting conditions. The study and analysis of numerical models reproducing the cut of a material is a matter of interest in several areas; namely, the improvement of the material properties, the optimization of the process and tool geometries and the prediction of unexpected failures. The analysis of bi-dimensional (2D) models is the most common approach for different reasons. Just focusing on the simulation point of view, it is the simplest procedure, the cheapest in terms of computational cost and sometimes the only feasible numerical solution. However, many industrial machining processes, such as cutting, blanking, milling and drilling have not a possible simplification to 2D models. Actually even a simple turning processes for non-orthogonal cuts can not be simplified to 2D. This work present an upgrade of the PFEM techniques in order to deal with the 3D machining problems. We present recent improvements in the finite element formulation, the meshing re-connections and the contact detection. By applying these developments the PFEM has the capability for modelling a wide range of practical machining processes. In this paper the capacity of the formulation and the accuracy of the results are analyzed and validated with some representative examples. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.
- Published
- 2021
24. Design of flexible manufacturing systems on the basis of CAx software and virtual modeling.
- Author
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Kul'ga, K., Kitaev, A., Sidorov, I., and Kozhinov, D.
- Abstract
Structural synthesis of flexible manufacturing systems for the machining of batches of parts and subassemblies at the preliminary design (technical proposal) stage is considered, on the basis of CAx software and virtual modeling of the control system. This is the key stage of design, since the structural synthesis of the flexible manufacturing system largely determines the economic viability of the design as a whole. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
25. Resource efficiency analysis of lubricating strategies for machining processes using life cycle assessment methodology
- Author
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Julia Fischer, Liselotte Schebek, Jorge Cristóbal, Beatrix Becker, Alessio Campitelli, and Publica
- Subjects
high energy consumption ,020209 energy ,Strategy and Management ,Compressed air ,machining centers ,Resource efficiency ,02 engineering and technology ,environmental impact ,Industrial and Manufacturing Engineering ,machining process ,Inventory analysis ,flood lubrication ,metal working ,Machining ,Hazardous waste ,hazardous material ,Manufacturing ,minimum quantity lubrication ,0202 electrical engineering, electronic engineering, information engineering ,environmental technology ,resource efficiency ,Process engineering ,Life-cycle assessment ,lubrication ,0505 law ,General Environmental Science ,Life Cycle ,sustainable development ,manufacturing industries ,Renewable Energy, Sustainability and the Environment ,business.industry ,LCA ,05 social sciences ,Life Cycle Assessment (LCA) ,cast iron ,inventory analysis ,input and output ,floods ,050501 criminology ,Lubrication ,Environmental science ,energy utilization ,business ,hazards ,pressure vessel ,compressed air ,machining - Abstract
The enhancement of resource efficiency in the manufacturing industry is a major key to achieve sustainable development. The purpose of this paper is to investigate the resource efficiency of metal working processes using different lubrication strategies: flood lubrication (FL) and minimum quantity lubrication (MQL). Life Cycle Assessment (LCA) is a suitable methodology to assess the resource efficiency. In this paper a LCA is carried out for three different materials: aluminium, steel and cast iron. The process related data had been provided by practical measurements on state of the art machines and missing data derived from literature and expert interviews. The used input and output data for the inventory analysis is documented in this paper. In a hotspot analysis using LCA, fourteen impact categories from CML 2001 had been analysed. Finally, parameters with a high influence on the resource efficiency of machining processes were examined. The results of the LCA show that the significant parameters causing high environmental impacts are electricity, compressed air and FL oil. The comparison of the machining processes using FL and MQL technologies reveals that most of the analysed processes have a higher environmental impact using FL instead of MQL. This is mainly due to the high energy consumption for the lubricating pump and also because of the higher consumption of lubricants compared to MQL. Furthermore, the generation of hazardous waste, in form of used oil and used filter fleece also contributes. The MQL-technology requires less electricity and lubrication oil and avoids hazardous waste. However, the results show that the compressed air consumption of MQL is significantly higher compared to FL-related processes. Through this study, new and specific LCA datasets for drilling and milling for three working materials including two lubricating strategies (FL and MQL) are generated for further research.
- Published
- 2019
26. Modelling the dynamics of a large damped boring bar in a lathe
- Author
-
Martin Magnevall and Dan Östling
- Subjects
Acoustic devices ,Materials science ,business.product_category ,Bar (music) ,Bending modes ,Bending ,Degrees of freedom (mechanics) ,Damper ,Tuned mass damper ,medicine ,Internal turning ,Two-degree-of-freedom models ,Machining centers ,System behaviors ,General Environmental Science ,Tool clamping ,Vibration control ,Annan maskinteknik ,Tuned mass dampers ,business.industry ,Tool machines ,Stiffness ,Natural frequency ,Structural engineering ,Passive dampers ,Clamping ,Machine tool ,General Earth and Planetary Sciences ,Clamping conditions ,Other Mechanical Engineering ,Stiffness loss ,medicine.symptom ,business - Abstract
Boring bars with tuned mass dampers have a passive damper tuned with respect to the frequency of the first bending mode of the tool. When the tool is clamped into the machine tool there is a stiffness loss that lowers the natural frequency of the bar compared to ideal clamping conditions. For large tools the difference can be more than 35%, depending on clamping structure, tool size and overhang. In this paper we investigate a simple two-degree-of-freedom model for the tool-machine interaction consisting of a bending mode coupled with a rotational stiff mode. The model gives good insight into the system behavior and fits well with measurements. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the scientific committee of The 17th CIRP Conference on Modelling of Machining Operations open access
- Published
- 2019
27. Energy efficient machine tools
- Abstract
The growing global energy demand from industry results in significant ecological and economical costs. Aiming to decrease the impact of machining operations, an increasing number of research activities and publications regarding energy efficient machine tools and machining processes can be found in the literature. This keynote paper provides an overview of current machine- and process-related measures to improve the energy efficiency of metal cutting machine tools. Based on an analysis of the energy requirements of machine tool components, design measures to reduce the energy demand of main and support units are introduced. Next, methods for an energy efficient operation of machine tools are reviewed. Furthermore, latest developments and already available energy efficiency options in the machine tool industry are discussed. The paper concludes with recommendations and future research questions for more energy efficient machine tools.
- Published
- 2020
28. A sensor framework for combined data streams and in-situ characterization of machining processes
- Abstract
Machining vibrations is a critical phenomenon in the industry as they negatively affect the quality and tool-life. One common avoidance strategy for machining vibrations is the fine-tuning of process parameters, thus leading to longer production time. Our research addresses this challenge and uses different streams of data to classify problematic processes. Data streams of machining parameters, tool position, loads, vibration sensors, together with process plan data and cutting tool usage information, are visualized. Experiments are performed to derive classification criteria. These results are then used to observe vibrations in a five-axis machining center for further process adjustment., QC 20210505
- Published
- 2020
- Full Text
- View/download PDF
29. A multilayer shallow learning approach to variation prediction and variation source identification in multistage machining processes
- Abstract
Variation propagation modelling in multistage machining processes through use of analytical approaches has been widely investigated for the purposes of dimension prediction and variation source identification. Yet the variation prediction of complex features is non-trivial task to model mathematically. Moreover, the application of the variation propagation approaches and associated variation source identification techniques using Skin Model Shapes is unclear. This paper proposes a multilayer shallow neural network regression approach to predict geometrical deviations of parts given manufacturing errors. The neural network is trained on a simulated data, generated from machining simulation of a point cloud of a part. Further, given a point cloud data of a machined feature, the source of variation can be identified by optimally matching the deviation patterns of the actual surface with that of shallow neural network generated surface. To demonstrate the method, a two-stage machining process and a virtual part that has planar, cylindrical and torus features was considered. The geometric characteristics of machined features and the sources variation could be predicted at an error of 1% and 4.25%, respectively. This work extends the application of Skin Model Shapes in variation propagation analysis in multistage manufacturing. © 2020, The Author(s)., QC 20201201
- Published
- 2020
- Full Text
- View/download PDF
30. Mill Turn u SolidCAM-u
- Author
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Minđek, Martin and Bušić, Matija
- Subjects
alatni strojevi ,Mill Turn ,TEHNIČKE ZNANOSTI. Strojarstvo. Proizvodno strojarstvo ,machining centers ,SolidWorks ,SolidCAM ,TECHNICAL SCIENCES. Mechanical Engineering. Production Mechanical Engineering ,machines ,obradni centri - Abstract
U ovome završnome radu opisan je princip rada Mill turn u SolidCAM-u te su na primjeru objašnjeni i koraci samog rada. U uvodnom poglavlju navedeni su događaji koji su rezultirali razvitku numeričkog upravljanja alatnih strojeva te pojavi prve glodalice. Daljnjim razvojem strojevi su upravljani računalno pa se razvija CNC (engl. Computer Numerical Control) te isto tako i glodalice s više osi. Drugi i treći dio rada opisuju početke numeričkog upravljanja i razvoj CNC upravljanja. Također je opisan razvoj alatnih strojeva u Hrvatskoj te prve tvornice istih. Nadalje, u radu su opisane karakteristike obradnih centara te je prikazana osnovna podjela s obzirom na vrstu obrade. Zatim je detaljno opisan svaki od njih. Završna poglavlja razrađuju pojam Mill Turn u SolidCAM-u te zašto se on danas sve više koristi. Opisan je računalni program za modeliranje SolidWorks te softver za programiranje unutar njega SolidCAM. U SolidWorksu je najprije korak po korak detaljno opisano 3D modeliranje ispitnog zadatka. Kasnije je kroz dva stezanja i operacije tokarenja, glodanja i bušenja prikazano programiranje tog istog zadatka u programu SolidCAM. Na kraju su prikazane simulacije obrade. In this final paper, the working principle of the Mill turn in SolidCAM is described and the steps of the work are explained on an example. The introductory chapter lists the events that resulted in the development of numerical control of machines and the appearance of the first milling machine. With further development, the machines were controlled by computer so CNC (Computer Numerical Control) was developed, as well as multi-axis milling machines. The second and third parts of the paper describe the beginnings of numerical control and the development of CNC control. The development of machines in Croatia and their first factories are also described. Furthermore, the paper describes the characteristics of machining centers and presents the basic division with regard to the type of machining. Each of them is then described in detail. The final chapters elaborate on the term Mill Turn in SolidCAM and why it is increasingly used today. The computer modeling model SolidWorks and the software for programming inside it SolidCAM are described. In SolidWorks, 3D modeling of the test task is first described in detail step by step. Later, through two clamps and turning, milling and drilling operations, the programming of the same task in SolidCAM was shown. Finally, processing simulations are presented.
- Published
- 2020
31. Energy efficient machine tools
- Author
-
Sami Kara, Masahiko Mori, Marc-André Dittrich, Christian Brecher, Eberhard Abele, and Berend Denkena
- Subjects
0209 industrial biotechnology ,Global energy ,business.product_category ,Research activities ,Machine tool ,Computer science ,Machining operations ,02 engineering and technology ,Machine tool components ,Energy requirement ,Industrial and Manufacturing Engineering ,020901 industrial engineering & automation ,0203 mechanical engineering ,Machining ,Machining centers ,Global energy demand ,Mechanical Engineering ,Energy management ,Cutting tools ,Energy efficient operations ,Dewey Decimal Classification::600 | Technik ,Manufacturing engineering ,Metal cutting ,020303 mechanical engineering & transports ,Energy efficiency ,Available energy ,Machine tool industry ,Energy-efficient machine ,Research questions ,Energy requirements ,business ,ddc:600 ,Efficient energy use - Abstract
The growing global energy demand from industry results in significant ecological and economical costs. Aiming to decrease the impact of machining operations, an increasing number of research activities and publications regarding energy efficient machine tools and machining processes can be found in the literature. This keynote paper provides an overview of current machine- and process-related measures to improve the energy efficiency of metal cutting machine tools. Based on an analysis of the energy requirements of machine tool components, design measures to reduce the energy demand of main and support units are introduced. Next, methods for an energy efficient operation of machine tools are reviewed. Furthermore, latest developments and already available energy efficiency options in the machine tool industry are discussed. The paper concludes with recommendations and future research questions for more energy efficient machine tools.
- Published
- 2020
- Full Text
- View/download PDF
32. The virtual design of machining centers for HSM: Towards new integrated tools.
- Author
-
Fortunato, Alessandro and Ascari, Alessandro
- Subjects
- *
COMPUTER-aided design , *COMPUTER architecture , *MATHEMATICAL models , *VIRTUAL design , *KINEMATICS , *TECHNOLOGICAL innovations , *FINITE element method , *PROTOTYPES - Abstract
Abstract: The virtual design of machining centers is a modern and well-known computer aided technique. Several modeling and simulation architectures, based on the lumped mass approach and on finite element method, are now well established and widely exploited worldwide. These solutions rapidly allow the basic setup of the kinematics of the feed drives and make possible a dynamic optimized dimensioning of all the main subsystems and structures of the machining center. This paper deals with research efforts aimed at developing an innovative and open design platform which allows the integration, in a user friendly framework, of the main procedures cited above with other design tools and facilities. An operator interface procedure and a package of input–output graphic routines, managed through a multilevel data base, are now active in this framework and interact with lumped mass and finite elements modules. According to these considerations the proposed tool allows to quickly and easily analyze alternative design solutions and makes possible to optimize the dynamic performances of the machine tool, helping the designer in the definition of the optimum machine tool characteristics before the manufacturing of the physical prototype. In order to demonstrate the potential of the proposed platform an example concerning the mass optimization of the Y axis of a gantry machining center is presented. [Copyright &y& Elsevier]
- Published
- 2013
- Full Text
- View/download PDF
33. Modelling the dynamics of a large damped boring bar in a lathe.
- Abstract
Boring bars with tuned mass dampers have a passive damper tuned with respect to the frequency of the first bending mode of the tool. When the tool is clamped into the machine tool there is a stiffness loss that lowers the natural frequency of the bar compared to ideal clamping conditions. For large tools the difference can be more than 35%, depending on clamping structure, tool size and overhang. In this paper we investigate a simple two-degree-of-freedom model for the tool-machine interaction consisting of a bending mode coupled with a rotational stiff mode. The model gives good insight into the system behavior and fits well with measurements. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the scientific committee of The 17th CIRP Conference on Modelling of Machining Operations, open access
- Published
- 2019
- Full Text
- View/download PDF
34. Improving technological machining simulation by tailored workpiece models and kinematics
- Abstract
Geometric modelling is an established approach for gathering detailed knowledge about the chronological sequence of process conditions and for determining technological values of machining processes such as milling, turning, grinding or additive manufacturing. Performance and accuracy essentially depend on the chosen workpiece model and its parametrization. Furthermore, several influences on the investigated machine tool system lead to errors, which must be modeled separately. This paper shows approaches to increase performance and accuracy of the simulation by choosing an appropriate combination of different geometric representations of the workpiece and by considering possible errors within the kinematic model. Examples for different applications in metal cutting are given.
- Published
- 2019
35. Optimization of complex cutting tools using a multi-dexel based material removal simulation
- Abstract
Multi-dexel based material removal simulations provide a fast and flexible way to compute process forces and tool deflections for milling and turning operations. This allows an advanced process planning including detection of collisions for complex toolpaths. However, using dexel simulations for designing cutting tools has rarely been investigated. Especially the position of individual cutting edges is not considered, because current approaches only subtract the sweep volume of the tool envelop instead of the rake face. This paper presents a new method to design cutting tools using material removal simulations and a detailed tool geometry representation. The discretization of the tool allows an efficient calculation of the engagement conditions of individual cutting edges. The method is used to optimize novel porcupine milling cutters with round indexeble inserts, which produces a geometry analogous to serrated end mills. Based on the calculated forces, the positions of individual indexable inserts are adjusted to minimize the maximum radial force. An optimum has been found that reduces radial force by 12% compared to conventional porcupine milling cutters with squared inserts. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the scientific committee of The 17th CIRP Conference on Modelling of Machining Operations
- Published
- 2019
36. Modelling the dynamics of a large damped boring bar in a lathe.
- Abstract
Boring bars with tuned mass dampers have a passive damper tuned with respect to the frequency of the first bending mode of the tool. When the tool is clamped into the machine tool there is a stiffness loss that lowers the natural frequency of the bar compared to ideal clamping conditions. For large tools the difference can be more than 35%, depending on clamping structure, tool size and overhang. In this paper we investigate a simple two-degree-of-freedom model for the tool-machine interaction consisting of a bending mode coupled with a rotational stiff mode. The model gives good insight into the system behavior and fits well with measurements. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the scientific committee of The 17th CIRP Conference on Modelling of Machining Operations, open access
- Published
- 2019
- Full Text
- View/download PDF
37. Modelling the dynamics of a large damped boring bar in a lathe.
- Abstract
Boring bars with tuned mass dampers have a passive damper tuned with respect to the frequency of the first bending mode of the tool. When the tool is clamped into the machine tool there is a stiffness loss that lowers the natural frequency of the bar compared to ideal clamping conditions. For large tools the difference can be more than 35%, depending on clamping structure, tool size and overhang. In this paper we investigate a simple two-degree-of-freedom model for the tool-machine interaction consisting of a bending mode coupled with a rotational stiff mode. The model gives good insight into the system behavior and fits well with measurements. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the scientific committee of The 17th CIRP Conference on Modelling of Machining Operations
- Published
- 2019
- Full Text
- View/download PDF
38. Modelling the dynamics of a large damped boring bar in a lathe.
- Abstract
Boring bars with tuned mass dampers have a passive damper tuned with respect to the frequency of the first bending mode of the tool. When the tool is clamped into the machine tool there is a stiffness loss that lowers the natural frequency of the bar compared to ideal clamping conditions. For large tools the difference can be more than 35%, depending on clamping structure, tool size and overhang. In this paper we investigate a simple two-degree-of-freedom model for the tool-machine interaction consisting of a bending mode coupled with a rotational stiff mode. The model gives good insight into the system behavior and fits well with measurements. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the scientific committee of The 17th CIRP Conference on Modelling of Machining Operations, open access
- Published
- 2019
- Full Text
- View/download PDF
39. Modelling the dynamics of a large damped boring bar in a lathe.
- Abstract
Boring bars with tuned mass dampers have a passive damper tuned with respect to the frequency of the first bending mode of the tool. When the tool is clamped into the machine tool there is a stiffness loss that lowers the natural frequency of the bar compared to ideal clamping conditions. For large tools the difference can be more than 35%, depending on clamping structure, tool size and overhang. In this paper we investigate a simple two-degree-of-freedom model for the tool-machine interaction consisting of a bending mode coupled with a rotational stiff mode. The model gives good insight into the system behavior and fits well with measurements. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the scientific committee of The 17th CIRP Conference on Modelling of Machining Operations, open access
- Published
- 2019
- Full Text
- View/download PDF
40. Modelling the dynamics of a large damped boring bar in a lathe.
- Abstract
Boring bars with tuned mass dampers have a passive damper tuned with respect to the frequency of the first bending mode of the tool. When the tool is clamped into the machine tool there is a stiffness loss that lowers the natural frequency of the bar compared to ideal clamping conditions. For large tools the difference can be more than 35%, depending on clamping structure, tool size and overhang. In this paper we investigate a simple two-degree-of-freedom model for the tool-machine interaction consisting of a bending mode coupled with a rotational stiff mode. The model gives good insight into the system behavior and fits well with measurements. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the scientific committee of The 17th CIRP Conference on Modelling of Machining Operations, open access
- Published
- 2019
- Full Text
- View/download PDF
41. Modelling the dynamics of a large damped boring bar in a lathe.
- Abstract
Boring bars with tuned mass dampers have a passive damper tuned with respect to the frequency of the first bending mode of the tool. When the tool is clamped into the machine tool there is a stiffness loss that lowers the natural frequency of the bar compared to ideal clamping conditions. For large tools the difference can be more than 35%, depending on clamping structure, tool size and overhang. In this paper we investigate a simple two-degree-of-freedom model for the tool-machine interaction consisting of a bending mode coupled with a rotational stiff mode. The model gives good insight into the system behavior and fits well with measurements. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the scientific committee of The 17th CIRP Conference on Modelling of Machining Operations, open access
- Published
- 2019
- Full Text
- View/download PDF
42. A Rolling Horizon Approach to Plan Outsourcing in Manufacturing-to-Order Environments Affected by Uncertainty.
- Author
-
Tolio, T. and Urgo, M.
- Subjects
PRODUCTION planning ,CONTRACTING out ,MANUFACTURING processes ,MANUFACTURING industries ,BUSINESS negotiation ,STOCHASTIC programming - Abstract
Abstract: Production planning approaches considering availability of complete information, usually fail to deal with real manufacturing environments characterized by uncertainty affecting the time to execute the manufacturing operations, the routing of the parts, the requirement of materials and resources. This paper analyses the problem of negotiation and planning of external resource usage in a manufacturing system affected by uncertainty. In particular the need of resources is considered uncertain and it is modelled through a scenario based formulation. A rolling horizon approach is proposed which applies a two-stage stochastic programming method against the occurrence of multiple uncertain events.To demonstrate the viability of the proposed approach, an application example based on a real manufacturing plant producing machining centres is provided. [Copyright &y& Elsevier]
- Published
- 2007
- Full Text
- View/download PDF
43. Improving technological machining simulation by tailored workpiece models and kinematics
- Author
-
Hai Nam Nguyen, Volker Böß, Marc-André Dittrich, Berend Denkena, and Bernd Breidenstein
- Subjects
0209 industrial biotechnology ,business.product_category ,Kinematics ,Dewey Decimal Classification::600 | Technik::670 | Industrielle und handwerkliche Fertigung ,Computer science ,Machine tool systems ,Mechanical engineering ,Geometry ,Machining Process ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Chronological sequences ,020901 industrial engineering & automation ,Geometric representation ,Machining ,ddc:670 ,Process condition ,Machining centers ,Milling ,Konferenzschrift ,0105 earth and related environmental sciences ,General Environmental Science ,Sequence ,Grinding ,Dewey Decimal Classification::600 | Technik ,Machine tool ,Metal cutting ,Geometric design ,General Earth and Planetary Sciences ,Machining simulation ,business ,Parametrization ,ddc:600 ,Geometric modelling ,Milling (machining) ,Simulation ,Grinding (machining) - Abstract
Geometric modelling is an established approach for gathering detailed knowledge about the chronological sequence of process conditions and for determining technological values of machining processes such as milling, turning, grinding or additive manufacturing. Performance and accuracy essentially depend on the chosen workpiece model and its parametrization. Furthermore, several influences on the investigated machine tool system lead to errors, which must be modeled separately. This paper shows approaches to increase performance and accuracy of the simulation by choosing an appropriate combination of different geometric representations of the workpiece and by considering possible errors within the kinematic model. Examples for different applications in metal cutting are given.
- Published
- 2019
44. Optimization of complex cutting tools using a multi-dexel based material removal simulation
- Author
-
O. Pape, Thilo Grove, and Berend Denkena
- Subjects
Optimization ,0209 industrial biotechnology ,Turning ,Discretization ,Material removal ,Computer science ,Dewey Decimal Classification::600 | Technik::670 | Industrielle und handwerkliche Fertigung ,Mechanical engineering ,Geometry ,02 engineering and technology ,Serrated end mills ,010501 environmental sciences ,01 natural sciences ,Dexel ,Indexable inserts ,020901 industrial engineering & automation ,Position (vector) ,ddc:670 ,Machining centers ,Representation (mathematics) ,Turning operations ,Konferenzschrift ,0105 earth and related environmental sciences ,General Environmental Science ,Milling cutters ,Rake ,Process (computing) ,Cutting tools ,Dewey Decimal Classification::600 | Technik ,Discretizations ,Face (geometry) ,General Earth and Planetary Sciences ,Geometric modeling ,Advanced process ,Simulaton ,ddc:600 ,Milling (machining) - Abstract
Multi-dexel based material removal simulations provide a fast and flexible way to compute process forces and tool deflections for milling and turning operations. This allows an advanced process planning including detection of collisions for complex toolpaths. However, using dexel simulations for designing cutting tools has rarely been investigated. Especially the position of individual cutting edges is not considered, because current approaches only subtract the sweep volume of the tool envelop instead of the rake face. This paper presents a new method to design cutting tools using material removal simulations and a detailed tool geometry representation. The discretization of the tool allows an efficient calculation of the engagement conditions of individual cutting edges. The method is used to optimize novel porcupine milling cutters with round indexeble inserts, which produces a geometry analogous to serrated end mills. Based on the calculated forces, the positions of individual indexable inserts are adjusted to minimize the maximum radial force. An optimum has been found that reduces radial force by 12% compared to conventional porcupine milling cutters with squared inserts. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the scientific committee of The 17th CIRP Conference on Modelling of Machining Operations
- Published
- 2019
- Full Text
- View/download PDF
45. Design of flexible manufacturing systems on the basis of CAx software and virtual modeling
- Author
-
Kul’ga, K. S., Kitaev, A. A., Sidorov, I. O., and Kozhinov, D. G.
- Published
- 2016
- Full Text
- View/download PDF
46. Inverse Determination of Constitutive Equations and Cutting Force Modelling for Complex Tools Using Oxley's Predictive Machining Theory
- Author
-
Thilo Grove, Marc-André Dittrich, Berend Denkena, D. Niederwestberg, and M. Lahres
- Subjects
Inverse problems ,Engineering ,Computation theory ,Finite element method ,Computation ,Constitutive equation ,Mechanical engineering ,Material ,Stress (mechanics) ,Machining ,Carbon steel ,Constitutive parameters ,Constitutive equations ,Machining centers ,ddc:510 ,Ultrahigh carbon steel ,Materials ,Material removal model ,Dewey Decimal Classification::500 | Naturwissenschaften ,Force ,Konferenzschrift ,General Environmental Science ,Complex tool geometry ,business.industry ,Chip formation ,Temperature calculation ,Cutting tools ,Inverse problem ,Dewey Decimal Classification::500 | Naturwissenschaften::510 | Mathematik ,Carbon ,Rake angle ,Undeformed chip thickness ,Constitutive models ,Cutting ,Particle swarm optimization (PSO) ,General Earth and Planetary Sciences ,ddc:500 ,business ,Simulation - Abstract
In analysis of machining processes, finite element analysis is widely used to predict forces, stress distributions, temperatures and chip formation. However, constitutive models are not always available and simulation of cutting processes with complex tool geometries can lead to extensive computation time. This article presents an approach to determine constitutive parameters of the Johnson-Cook's flow stress model by inverse modelling as well as a methodology to predict process forces and temperatures for complex three-dimensional tools using Oxley's machining theory. In the first part of this study, an analytically based computer code combined with a particle swarm optimization (PSO) algorithm is used to identify constitutive models for 70MnVS4 and an aluminium-alloyed ultra-high-carbon steel (UHC-steel) from orthogonal milling experiments. In the second part, Oxley's predictive machining theory is coupled with a multi-dexel based material removal model. Contact zone information (width of cut, undeformed chip thickness, rake angle and cutting speed) are calculated for incremental segments on the cutting edge and used as input parameters for force and temperature calculations. Subsequently, process forces are predicted for machining using the inverse determined constitutive models and compared to actual force measurements. The suggested methodology has advantages regarding the computation time compared to finite element analyses. BMBF/02PN2050
- Published
- 2015
- Full Text
- View/download PDF
47. Prediction of the 3D Surface Topography after Ball End Milling and its Influence on Aerodynamics
- Author
-
D. Nespor, Volker Böß, S. Hohenstein, Philipp Gilge, Berend Denkena, and Jörg Seume
- Subjects
Ball end mill ,Machining process ,Empirical data ,Engineering ,Topography ,Kinematics ,Machining Process ,Mechanical engineering ,Turbine ,Surface topography ,Ball milling ,Machining ,Machining centers ,Dewey Decimal Classification::500 | Naturwissenschaften ,Konferenzschrift ,Milling ,General Environmental Science ,3-D surface topography ,Stochastic systems ,business.industry ,Surface prediction ,Ball end milling ,Aerodynamics ,Turbomachine blades ,Vibration ,Ball (bearing) ,General Earth and Planetary Sciences ,ddc:500 ,Machining simulation ,business ,Milling (machining) ,Simulation ,Forecasting - Abstract
The surface topography of milled workpieces often defines their performance. One example is blades in turbine engines, where the topography defines the flow losses. This type of complex goods is often machined by ball end mills, either for manufacture or repair. The literature offers various model types to predict the surface topography in order to design a machining process without prior experiment. The most accurate models use the real kinematics of the process and blend the tool with the workpiece. But this type of surface prediction ignores the differences between the reality and the simulation due to vibrations, tool chipping etc. This paper presents a combined approach using the kinematic topography from the machining simulation and adds a stochastic topography based on empirical data. It could be shown, that the usage of the stochastic topography greatly affects the flow losses and thus cannot be ignored. DFG/CRC/871
- Published
- 2015
- Full Text
- View/download PDF
48. Thermocouple and Infrared Sensor-Based Measurement of Temperature Distribution in Metal Cutting
- Author
-
Salih Coşkun, M. Cemal Cakir, Abdil Kuş, Kadir Özdemir, Yahya Isik, Uludağ Üniversitesi/Teknik Bilimler Meslek Yüksekokulu., Uludağ Üniversitesi/Mühendislik Fakültesi/Makine Mühendisliği Bölümü., Kuş, Abdil, Işık, Yahya, Çakır, Cemal M., Coşkun, Salih, Özdemir, Kadir, and AAG-9412-2021
- Subjects
Turning ,Mechanical engineering ,Hardware_PERFORMANCEANDRELIABILITY ,Engineering, electrical & electronic ,lcsh:Chemical technology ,Metal Cutting ,Cutting Process ,Tool Wear ,Biochemistry ,Analytical Chemistry ,law.invention ,Carbide ,Computer Science::Hardware Architecture ,tool temperature ,Engineering ,Tool temperatures ,Machining ,Thermocouple ,law ,Tool-chip interface temperatures ,lcsh:TP1-1185 ,Thermal analysis ,Infrared radiation ,Instrumentation ,Pyrometers ,ANSYS finite element method ,Pyrometer ,Cutting tool ,pyrometer ,Electromagnetic wave emission ,Atomic and Molecular Physics, and Optics ,thermocouple ,Pyrometry ,Chemistry ,Metal cutting ,Thermocouples ,Orthogonal machining ,cutting speed ,K-type thermocouples ,Carbides ,Infrared detectors ,machining ,Instruments & instrumentation ,Finite element method ,Alloy steel ,engineering.material ,Temperature measurement ,Article ,Effective parameters ,Hardware_INTEGRATEDCIRCUITS ,Machining centers ,Electrical and Electronic Engineering ,business.industry ,Chemistry, analytical ,Cutting tools ,Thermoanalysis ,Cutting ,ComputerSystemsOrganization_MISCELLANEOUS ,engineering ,Measurement of temperature ,business - Abstract
In metal cutting, the magnitude of the temperature at the tool-chip interface is a function of the cutting parameters. This temperature directly affects production, therefore, increased research on the role of cutting temperatures can lead to improved machining operations. In this study, tool temperature was estimated by simultaneous temperature measurement employing both a K-type thermocouple and an infrared radiation (IR) pyrometer to measure the tool-chip interface temperature. Due to the complexity of the machining processes, the integration of different measuring techniques was necessary in order to obtain consistent temperature data. The thermal analysis results were compared via the ANSYS finite element method. Experiments were carried out in dry machining using workpiece material of AISI 4140 alloy steel that was heat treated by an induction process to a hardness of 50 HRC. A PVD TiAlN-TiN-coated WNVG 080404-IC907 carbide insert was used during the turning process. The results showed that with increasing cutting speed, feed rate and depth of cut, the tool temperature increased, the cutting speed was found to be the most effective parameter in assessing the temperature rise. The heat distribution of the cutting tool, tool-chip interface and workpiece provided effective and useful data for the optimization of selected cutting parameters during orthogonal machining.
- Published
- 2015
49. Prediction of Temperature Induced Shape Deviations in dry Milling
- Author
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D. Niederwestberg, Jost Vehmeyer, Alfred Schmidt, Peter Maaß, Berend Denkena, and Carsten Niebuhr
- Subjects
geometric modelling ,Finite element method ,Materials science ,Discretization ,Material removal ,Mechanical engineering ,Boundary (topology) ,Dry milling ,Deformation (meteorology) ,Dexel ,Thermoelastic damping ,Machining ,Machining centers ,Konferenzschrift ,General Environmental Science ,Finite element method (FEM) ,finite element method (FEM) ,deformation ,material removal ,Mechanics ,simulation ,Dewey Decimal Classification::600 | Technik ,Deformation ,Heat flux ,General Earth and Planetary Sciences ,Thermal error ,thermal error ,ddc:600 ,Milling (machining) ,Geometric modelling ,Simulation ,dry milling ,Forecasting - Abstract
In this paper a model for a simulation based prediction of temperature induced shape deviations in dry milling is presented. A closed loop between Boolean material removal, process forces, heat flux and thermoelastic deformation is established. Therefore, an efficient dexel based machining simulation is extended by a contact zone analysis to model the local workpiece load. Based on the computed contact zone the cutting forces and heat flux are calculated using a semi-empirical process model. For a detailed consideration of the loads they are discretized and localized on the dexel-represented workpiece surface. A projection of the localized workpiece loads on the boundary of the finite element domain, taking into account the Boolean material removal during the process, allows the calculation of the current temperature and deformation of the workpiece. By transforming these thermomechanical characteristics back to the dexel-model a consideration in the machining simulation is possible. An extended contact zone analysis is developed for the prediction of the localized shape deviations. Finally, the results of the simulation are compared with measured data. The comparison shows that workpiece temperatures, workpiece deformation and shape deviations in different workpiece areas are predicted accurately. DFG/DE 447/90-2 DFG/MA 1657/21-2
- Published
- 2015
- Full Text
- View/download PDF
50. Sound Analysis in Drilling, Frequency and Time Domains
- Abstract
This paper proposes a guideline for interpreting frequency content and time history of sound measurements in metal drilling processes. Different dynamic phenomena are reflected in generated sound in cutting processes. The footprint of such phenomena including torsional, lateral regenerative chatter and whirling in sound measurement results are discussed. Different indexable insert drills, at several cutting conditions, are covered. The proposed analysis could be used for studying, online monitoring and controlling of drilling processes. © 2017 The Authors., CC BY-NC-ND 4.0Available online 31 May 2017This paper is the result of a joint project between Sandvik Coromant and University West, Sweden. Resources provided by SiCoMaP and the Knowledge Foundation (KK-stiftelsen) are greatly appreciated.
- Published
- 2017
- Full Text
- View/download PDF
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