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This paper aims to develop an integrated Quality–Cost–Environmental (QCE) indicator for the selection of photovoltaic panels (PVps) offered to customers, considering the following criteria: (i) quality satisfaction; (ii) cost-effectiveness; and (iii) environmental impact throughout the life cycle. The proposed QCE indicator was developed within a framework that incorporated an FAHP (Fuzzy Analytic Hierarchy Process), cost-effectiveness analysis (CEA), and life cycle assessment (LCA). The model test confirmed its effectiveness in choosing a PVp which combines environmental friendliness throughout its entire life cycle with satisfactory quality and a reasonable purchase price for customers. The proposed model can be utilized by individuals, businesses, and public entities for the selection of high-quality, cost-efficient, and environmentally friendly PVps—thereby promoting sustainable development. [ABSTRACT FROM AUTHOR]

In engineering courses with a large number of students, fail and dropout rates are usually high even in courses that can be expected to be interesting to the students. Gamification tools have arisen as an interesting way to motivate the students for a real continuous assessment, increasing the student's attendance and performance. In this paper, a gamification approach based on a Kahoot tool, Moodle activities, and commemorative badges is proposed within a manufacturing course. The designed activities let the students compete among themselves to get the maximum number of points, which will be converted into extra grades that are added to the final exam grade. The gamification experience has been proven to be highly positive according to students' and instructors' perceptions, and the average increase of pass rate and course attendance with respect to previous years have increased from 22% to 34% and from 38% to 66%, respectively. [ABSTRACT FROM AUTHOR]

Automated post weld treatment for offshore wind turbines A more economical and resource‐saving construction of offshore wind energy converters (OWEC) is necessary in order to implement climate policy objectives. The increase of the fatigue resistance by using high‐strength steels and by applying post‐weld treatment methods offers great potential for reducing the use of materials and costs for monopiles. Specifically, in the automated OWEC manufacturing chain, automated processes such as deep rolling are a suitable option. Deep rolling is an established process in mechanical engineering for increasing the wear and fatigue resistance of metallic components. This paper presents results of deep rolling as a new post treatment method to increase the fatigue strength of welds. The surface and subsurface zone properties of submerged arc welded butt joints made of a structural steel grade S355MLO before and after deep rolling are shown. In order to quantify the influence of deep rolling on the weld geometry, measurements of a laser line sensor are presented. Finally, the results of fatigue tests are discussed, which show the great potential of the deep rolling process as a post weld treatment method. [ABSTRACT FROM AUTHOR]

In industry, today's approach to assembly design is still largely based on a bottom-up approach which, in contrast with the most advanced top-down techniques, is unfit to deal with very large and complex products. The reason for this lies in the high number of relationships to be established between parts and in the lack of a high-level control of the assembly design. This makes the management of design changes a labor-intensive process and the capture of design intent difficult to achieve. The paper, referring to the most advanced research fields of Concurrent Engineering and Knowledge-Based Engineering, focuses on a top-down modelling approach based on skeleton, which constitutes the most natural but still scarcely exploited way to attain a high reactivity to design modifications. Through the application of suitable methodologies, such as that one for a SKeLeton geometry-based Assembly Context Definition (SKL-ACD), the skeleton is also able to capture and codify assembly process engineering information since the early phases of the product development process. With the purpose of promoting the knowledge of these skeleton-based modelling techniques, that have a great relevance for training professional, technical and mechanical engineers, this paper implements the SKLACD methodology to an industrial case study in order to identify, with a unique and repeatable workflow, the reference geometrical entities and the mutual relationships to embed into the product skeleton. The skeleton types and the related fields of use are also described, placing particular emphasis on problems or shortcomings still not resolved, especially in consideration of the need to assist the designer in defining the impact of a parameter on assembly modification and in avoiding loops while defining formulas. A new tool, in the form of a multilayer graph, is finally proposed that is able to display and differentiate clearly the formulas, the design parameters and the impact of their modification on skeleton entities and members of the assembly. [ABSTRACT FROM AUTHOR]

Tamping process in railway engineering Mechanical model of the tamping unit‐ballast matrix interaction. Condition of the ballast bed is one of the most important parameters for safe and economical operation of railway systems. In order to define the optimum time for ballast bed cleaning or renewal as well as to improve ballast serviceability and track life cycle performance, better knowledge of the ballast bed condition, i.e. definition of the degree of ballast fouling is of crucial importance. As a core maintenance activity in ballasted track, the tamping process influences the economical service life of the track to a great extent and is essential in restoring the track geometry for safe train operations. During the tamping process, the tamping tines interact with the ballast matrix, transferring the displacement caused by the dynamic excitation overlapped with the extension in the hydraulic cylinder to the ballast, compacting it under the sleeper. This interaction is observed and measured in‐situ in several locations in Austria. Serving as a mean of comparison and confirmation with the conducted in‐situ measurements, a semi‐analytical model of the tamping unit – ballast matrix interaction has been developed. Conclusions regarding the differences in response and resistance to compaction of both new and fouled ballast material are made and presented in this paper. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to design the process of quality management at the engineering enterprises of Azerbaijan. On the basis of previous works, authors propose the procedure for definition of management processes by production quality according to ISO 9001--2001. Also the article describes the ways of establishment of integrated systems of quality management with business orientation. It is concluded that in search of optimal solutions in the quality management system, in the evaluation of stakeholders' satisfaction with engineering production quality, the theory of inaccurate sets can be applied. Further research may be appointed in order to develop methods for modeling and optimization in the process of manufacturing engineering products, as well as the use of software systems. This paper provides new evidence about a still unexplored topic, trying to bridge the existing gap in the literature about the quality management system and its implementation at the Azerbaijan enterprises. [ABSTRACT FROM AUTHOR]

Aim: The aim of this paper is to present an optimization proposal in the automated guided vehicles design used in hospital logistics, as well as to analyze the impact of its implementation in a real environment. Method: This proposal is based on the design of those elements that would allow the vehicles to deliver an extra cart by the towing method. So, the proposal intention is to improve the productivity and the performance of the current vehicles by using a transportation method of combined carts. Results: The study has been developed following concurrent engineering premises from three different viewpoints. First, the sequence of operations has been described, and second, a proposal of design of the equipment has been undertaken. Finally, the impact of the proposal has been analyzed according to real data from the Hospital Universitario Rio Hortega in Valladolid (Spain). In this particular case, by the implementation of the analyzed proposal in the hospital a reduction of over 35% of the current time of use can be achieved. This result may allow adding new tasks to the vehicles, and according to this, both a new kind of vehicle and a specific module can be developed in order to get a better performance. [ABSTRACT FROM AUTHOR]

Engineering of manufacturing systems is one of the most important aspects within the life cycle of manufacturing systems in terms of cost. Within the engineering process, several engineering activities are executed by different experts commonly using specific tools for the design of the different parts of the system. To reduce engineering costs beneath, two main approaches arise. The first is based on the use of libraries of mechatronical units as reusable artifacts. In this case, manufacturing systems are represented as a hierarchy of mechatronic units. The second option is to achieve the seamless connection of the different engineering tools exploiting a common data exchange format. This latter approach allows avoiding both double engineering and faults within the engineering process. Within this paper, a novel approach combining both options is proposed, and its effects are analyzed through an example. It considers the application of mechatronical units within the engineering process of manufacturing systems as well as a common data exchange format for the logic information required for designing the control system within the engineering of manufacturing systems. The latter provides a data exchange format for the overall engineering process, including not only model information exchange but also its embedding. This paper discusses the benefits of the data exchange format for logic models in detail. [ABSTRACT FROM AUTHOR]

This paper presents a contribution to the diagnosis of scientificresearch evaluation in Brazil, supported by a national database dubbed "Qualis". Capes is the governmental institution in charge of the development and management of this database, which presents the classification of journals and is an important tool for the improvement of Brazilian scientific research. The present paper identifies the major difficulties in research evaluation and provides an analysis of the latest changes regarding the criteria which are applied within the field of "Engineering III", which includes: Aerospace Engineering, Production Engineering, Mechanical Engineering, Petroleum Engineering and Naval/Ocean Engineering. The analysis comprises a discussion of proposals for improvement and a conceptual map showing synthetically the interrelationships among the concepts utilized in the study. In addition, it presents some suggestions which are specific for the context of Operations Research. [ABSTRACT FROM AUTHOR]

The article presents abstracts of several papers related to mechanical engineering which were published in various journals. Some of the papers are "Multi-Dimensional Vibration Power Flow Analysis of Compressor System Mounted in Outdoor Unit of an Air Conditioner," by Lee, H.J. and K.J. Kim, "Longitudinal Vibration Modeling and Control of a Flexible Transporter System With Arbitrarily Varying Cable Lengths," by Zhang. Y., S.K. Agrawal, and P. Hagedorn, "Misfire Detection of Locomotive Diesel Engine by Non-Linear Analysis," by Bogus. P. and J. Merkisz.

In this paper, a permeability measurement method using hybrid fiber preforms is presented. The hybrid fiber preform can be composed of different fiber mat types, different numbers of fiber mats of the same type, or both. The computational procedure for permeability based on flow front location and flow time data was derived. This approach was validated by both simulation and experimental studies. The results show that by using this method, permeability values of different fiber mat types or the relationship between permeability and fiber volume fraction (porosity) can be obtained through a single experiment. This permeability measurement method based on hybrid fiber preforms yields compatible measurement accuracies while significantly improving the measurement efficiency. It provides a fast, accurate, and easy-to-use approach for permeability characterization, which is of great significance for the integrated composite product and process development. In this paper, a permeability measurement method using hybrid fiber preforms is presented. The hybrid fiber preform can be composed of different fiber mat types, different numbers of fiber mats of the same type, or both. The computational procedure for permeability based on flow front location and flow time data was derived. This approach was validated by both simulation and experimental studies. The results show that by using this method, permeability values of different fiber mat types or the relationship between permeability and fiber volume fraction (porosity) can be obtained through a single experiment. This permeability measurement method based on hybrid fiber preforms yields compatible measurement accuracies while significantly improving the measurement efficiency. It provides a fast, accurate, and easy-to-use approach for permeability characterization, which is of great significance for the integrated composite product and process development. [ABSTRACT FROM AUTHOR]

This paper presents a study on dimensional variations and tolerance analysis and synthesis for polymer matrix fiber-reinforced composite components and assemblies. A composite component dimensional variation model was developed with process simulation based on thermal stress analysis and finite element analysis (FEA ). Using the FEA-based dimensional variation model the deformations of typical composite structures were studied and the regression-based dimensional variation models were developed. The regression-based dimensional variation models can significantly reduce computation time and provide a quick design guide for composite products with reduced dimensional variations. By introducing a material modification coefficient, the comprehensive regression models can handle various fiber and resin types and stacking sequences, which eliminates the complicated, time-consuming finite element meshing and material parameter defining process. A structural tree method (STM) was developed for rapid computation of composite assembly dimensional variations resulting from deformations on individual components, as well as the deformation of composite components with complex shapes. With the STM and the regression-based dimensional variation models, rapid design optimization was conducted to reduce the dimensional variations of composite assemblies. Cost-tolerance functions were developed using a fuzzy multiattribute utility theory based cost-estimation method. Based on the developed dimensional variation and cost-tolerance models, composite assembly tolerance analysis and synthesis were performed in this study. The exploring research work presented in this paper provides a foundation for developing practical and productive dimensional control techniques for composite products. [ABSTRACT FROM AUTHOR]

Optimizing the milling process requires a priori knowledge of injury process variables. However, the ability to include both milling stability and accuracy information is limited because current methods do not provide simultaneous milling stability and accuracy predictions. The method described within this paper, called Temporal Finite Element Analysis (TFEA), provides an approach for simultaneous prediction of milling stability and surface location error. This paper details the application of this approach to a multiple mode system in two orthogonal directions. The TFEA method forms an approximate analytical solution by dividing the time in the cut into a finite number of elements. The approximate solution is then matched with the exact solution for free vibration to obtain a discrete linear map. The formulated dynamic map is then used u, determine stability steady-state surface location error, and to reconstruct the time series for a stable cutting process. Solution convergence is evaluated by simply increasing the number of elements and through comparisons with numerical integration. Analytical predictions are compared to several different milling experiments. An interesting period two behavior, which was originally believed to be a flip bifurcation, was observed during experiment. However, evidence is presented to show this behavior can be attributed to runout in the cutter teeth. [ABSTRACT FROM AUTHOR]

With society focusing more and more on environmental issues, the recycling of materials of all types has become an important concern. As a result of previous processing and usage, the properties of recycled materials are often significantly inferior when compared to their unrecycled counterparts. Recycled polymeric materials, for example, have lowered molecular weights caused by previous thermal and/or shear histories. Thus, the scope of application for recycled materials has traditionally been very limited. With the aid of a new processing concept known as vibration-assisted injection molding (VAIM), the mechanical properties of products containing recycled polymeric materials could be dramatically improved. The current paper presents the results of an initial experimental investigation into the application of VAIM for recycled polystyrene (Recycled-PS) products. A number of recycled/new material blends were studied, and in all cases significant product mechanical property enhancements were realized through the use of VAIM. It was concluded that VAIM molded products containing as much as 50% low-grade recycled material could be made stronger than products made using traditional molding with 100% new polymer. Detailed results are presented in the paper, along with some insight into the likely fundamental mechanism underlying the utility of the VAIM technique. [ABSTRACT FROM AUTHOR]

This paper discusses the microdeposition technologies used in the fabrication of meso- and microscale structures. The ability to process a wide range of materials and the flexibility to build functional and geometrically complex structures in meso- and microscale gives the microdeposition method some advantages over micromachining or lithography methods investigated extensively in the past In this paper work on deposition technology is reviewed, including material, supply of material, powder flow rate, and manipulation of particles and microdeposition technologies. The advantages and disadvantages of each technology are summarized at the end of the paper. [ABSTRACT FROM AUTHOR]

Quality control and metrology are critical to improved productivity and yield in MEMS design and production. This paper presents a micrograting interferometer for use in measuring MEMS devices, The sensor is also capable of making dynamic measurements, qualifying the functionality of the MEMS devices. The system employs a phase sensitive diffraction grating for interferometric axial resolution and a microfabricated lens for improved lateral resolution. The microinterferometer is capable of array implementation and can be used to increase the yield of MEMS manufacturing processes. The results generated by a single microinterferometer show good correlation with both analytic models and measurements of the MEMS devices by other metrology tools. The microinterferometer enables measurement of steady state vibration of MEMS devices as well as the development of surface vibration profiles. Initial results presented in this paper also demonstrate the ability to measure quantities such as part surface curvature, as well as reduce low frequency vibrational noise. The use of a deformable diffraction grating is proposed to further enhance the sensor's capabilities. [ABSTRACT FROM AUTHOR]

This paper discusses the development of an enhanced, static model of chip formation in micromilling processes that is able to describe the intermittency of the chip formation observed at low feeds per tooth due to the dominance of the minimum chip thickness effect Experimental analyses demonstrate the validity of the proposed model by verifying the level of periodicity in the cutting forces present at various feeds per tooth. A key finding of this study is the identification of a local maximum in the radial thrust forces in the micromilling process during the noncutting regime, at feeds per tooth that are of the order of the minimum chip thickness. To overcome the challenges in the direct measurement of the minimum chip thickness, this paper presents a method for estimating the minimum chip thickness of various combinations of tools and workpiece materials based on easily attainable cutting-force data. A discussion on the selection of process parameters to avoid intermittent chip formation is also presented. [ABSTRACT FROM AUTHOR]

Optical fibers are drawn from preforms (fused silica glass rods) typically made up of two concentric cylinders (the core rod and the clad tube), which are usually joined in a separate fusion process. The setup time and hence manufacturing cost can be significantly reduced if the two cylinders can be joined in the same furnace in which the fiber is drawn. A good understanding of the transient temperature distribution is needed for controlling the feed rate to avoid thermally induced cracks. Since direct measurement of the temperature fields is often impossible, the geometrical design of the preform and the control of the feed rate have largely been accomplished by trials-and-errors. The ability to predict the transient temperature distribution and the thermally induced stresses will provide a rational basis to design optimization and feed rate control of the process. In this paper we present an analytical model to predict the transient conductive-radiative transfer as two partially joined, concentric glass cylinders with specular surfaces are fed into the furnace. Finite volume method (FVM) is used to solve the radiative transfer equation (RTE). The specular surface reflectivity is obtained by the Fresnel's law and the Snell's law. The boundary intensities are obtained through the coupling of the interior glass radiative transfer and the exterior furnace enclosure analysis. The model has been used to numerically study the transient conductive-radiative transfer in the advanced melting zone (AMZ) of an optic fiber drawing process. This problem is of both theoretical and practical interest in the manufacture of optical fibers. The computational method for the radiation transfer developed in this paper can also be applied to the simulation of the fiber drawing process and other glass-related manufacturing processes. [ABSTRACT FROM AUTHOR]

The paper deals with logistics risk management safety program of new and renovated machines, which as members of the management of company must deal with. There are accountable consequences of untreated risks that may stop a dangerous event. In this case, damage can be life or health of users or it can create damage to their property i.e. that may end up as damage of the machine. Contribution from own perspective is focused on: defining the basic concepts of base solution, logistics system methodology management of technical risks and logistic system analysis of the machinery. [ABSTRACT FROM AUTHOR]

In certain domains of production engineering we are faced with very small batch production as it is the case in the production of heavy hydro energy equipment. In this domain manual welding is one of the most time consuming operations. Monitoring of the welding process is essential from the point of work organization as well as from the point of process control. In this paper a novel concept of data acquisition and recording of welding parameters to the welding diary is presented. Several considerations on signal acquisition, sampling rate, processing, data aggregation, wireless information transfer, and presentation are discussed. Implementation of the concept is discussed on laboratory and industrial examples. [ABSTRACT FROM AUTHOR]

The paper presents a method of selecting the parameters of external involute spur gearing components with straight and helical teeth for general - purpose gears, using the method of searching an area of possible solutions, understood as a space for values that meet several geometric, strength and operating criteria. Possible effects of this method in the context of gear production process organization and optimization, were also described. [ABSTRACT FROM AUTHOR]

Abstract: Sustainable development is seeking to meet the needs of the present without compromising those of future generations. The need to integrate the principles, values, and practices of sustainable development into all aspects of manufacturing, in order to address the social, economic, cultural and environmental problems is felt widely among the industrialized society. Selecting or identifying a suitable material or manufacturing processes is one way of achieving sustainability of a product by reducing its end of life impacts to a possible extent. But technological changes are unpredictable and so predicting future possible environmental impacts are highly difficult. This paper tries to explore the potential of environmental impact minimisation using alternative materials and alternative manufacturing processes. A case study has been carried out to in this regard in an Indian automotive component manufacturing organization. The results indicate that change in material has higher impact over the manufacturing process in reducing the environmental impact. [Copyright &y& Elsevier]

Gas meter has been modeled through many different simulation techniques in the recent times, suggesting new solution and giving new ways to minimize the material cost. In this project we will present an advanced simulation of the gas meter components, taking into account the maximum tensile strength and structural integrity. Our design presents a basic gas meter model to predict the behavior of structures while that it can withstand external & internal forces. Those points will be identified which are exceeding the limits of maximum tensile strength of the material. The result will show clear picture of the Von-Mises stresses, Strain, displacement and deformation. There are some inherent problems in simulation like time and memory consumption during analysis is huge. In this paper we shall analyze the gas meter and try to find a suitable solution for the inherent problems. [ABSTRACT FROM AUTHOR]

This paper deals with mechanical products process modeling for quality in order-handling manufacturing system. It investigates an influence of the product and process qualitatives-quantitatives indications to the manufacturing quality. The research is based on product design features peculiarities as material, geometrical form, dimensions, tolerances, and roughness of surfaces and so on. The graph theory for transformation of mechanical part drawings' data into digital codes has been applied. The developed model can forecast product manufacturing and quality cost at the early stage of a product design and also it is useful at the new business consideration phase in orderhandling manufacturing systems. Modeling of quality cost can decrease the risk of production errors in high variety and low volume manufacturing system rightly estimating its possibilities and suggesting decision making for creation of a right process structure and fabrication facility and tooling aiming the minimal production and quality costs. The created model is tested and validated in two Lithuanian manufacturing companies and it is able to use in mechanical engineering industry and also for study process in technical universities. [ABSTRACT FROM AUTHOR]

The flatness measurement of a large 2-D flat work- piece such as a satellite solar panel substrate is a key problem in its manufacturing process. Based on the current measuring methods and the actual engineering project, a new noncontact high-precision, low-cost large 2-D flat workpiece flatness measuring system is developed, in which the techniques of oblique optical triangle measuring structure, virtual measurement datum plane, and error self-correction are adopted. By means of the oblique optical triangle measuring structure that is first proposed, the measuring area and resolution of the measuring system can be greatly increased. Meanwhile, on the basis of the techniques of virtual measurement datum plane and error self-correction, the noncontact high-precision, low-cost flatness measurement can be realized on a nonprecise large metallic platform. Experimental results on the satellite solar panel substrate indicate the correctness and effectiveness of the proposed noncontact flatness-measuring system of the large 2-D flat workpiece. Although the specific application of the satellite solar panel substrate is presented in this paper, the proposed measurement techniques and measuring system could be applied independent of the nature or use of the large 2-D flat workpieces. [ABSTRACT FROM AUTHOR]

Size tolerance is the most critical parameter requiring attention for ensuring dimensional repeatability of manufactured component parts, yet very little research has been reported on this important topic. This paper presents a method for predicting size tolerances of component parts machined through peripheral end milling. The method makes use of prototype software based on previously reported cutting-force and surface-generation models in which the end mill is modelled as a cantilever beam rigidly gripped by the tool holder. It also takes into account the effect of size variation for the cutting tool. The method is validated through several cutting experiments. For further analysis, the method is employed for predicting the size tolerances of a prismatic component by varying one controllable variable at a time and then monitoring the relationship between size tolerance and the variable. When a distinct relationship is noted it is verified both analytically and experimentally. The results indicated that whilst the average size variation, which contributed to the variation of the basic size of component parts, is always proportional to the metal removal rate, the range of size variations that contributed to the size tolerance is not. Therefore, there is scope for increasing the metal removal rate without sacrificing the size tolerance. The knowledge acquired through this research can be applied for selecting an optimum cutting condition using the developed method when the size tolerances of component parts are specified. [ABSTRACT FROM AUTHOR]

Abstract: Fault tree analysis (FTA) is a technique that describes the combinations of events in a system which result in an undesirable outcome. FTA is used as a tool to quantitatively assess a system''s probability for an undesirable outcome. Time constraints from concept to production in modern engineering often limit the opportunity for a thorough statistical analysis of a system. Furthermore, when undesirable outcomes are considered such as hazard to human(s), it becomes difficult to identify strict statistical targets for what is acceptable. Consequently, when hazard to human(s) is concerned a common design target is to protect the system from single points of failure (SPOF) which means that no failure mode caused by a single event, concern, or error has a critical consequence on the system. Such a design target is common with “by-wire” systems. FTA can be used to verify if a system is protected from SPOF. In this paper, sufficient criteria for evaluating protection from SPOF for partially expanded fault trees are proposed along with proof. The proposed criteria consider potential interactions between the lowest drawn events of a partial fault tree expansion which otherwise easily leads to an overly optimistic analysis of protection from SPOF. The analysis is limited to fault trees that are coherent and static. [Copyright &y& Elsevier]

In recent years there has been a tremendous growth in the number of cell formation methods. The surge of interest in the area has been fueled by the substantial industry interest in implementing cellular manufacturing (CM) system to reduce movement of jobs, set-up times and lead times. In this paper, a new approach for cell formation that integrates machine grouping and layout design, neglecting part-family formation has been presented. The procedure includes four phases. In Phase 1, primary cells are formed by dividing operations into three ranges (high, medium and low). The frequency off low occurring between the operations has been taken as a measure for dividing flows into three ranges. Phase 2, involves redesigning of primary cells for minimization of the number of intercell travels and to address the machine duplication problem. Priority levels entered by the users solve the machine duplication problem. Phase 3, involves decomposition of individual primary cells into sub-cells. Sub-cells are formed by employing Phases 1 and 2 again on individual primary cells until further division into sub-cells becomes impossible. Phase 4, involves forced decomposition of sub-cells in order to obtain multiple cell designs. Multiple cell designs are based on criteria of maximum number of machines that can be accommodated in a cell. Multiple cell designs are formed by forcing excess operations to other cells based on the criteria of maximum number of operations that can be accommodated in a cell. The methodology is demonstrated using an illustrative example. [ABSTRACT FROM AUTHOR]

The design of plastic injection moulded part is a highly iterative process and depends largely on the human expertise including product designers, mould designers, manufacturing engineers, who need to possess thorough and broad specific knowledge and experience. The automatic recognition of features for injection moulded parts is the first prominent stage for any automatic design evaluation system. In this paper, features of plastic product are classified in three hierarchical levels of primitive features, complex features and high-level complex features. The proposed method adopts a hybrid approach, which combines the graph theoretic approach with the logic approach. Methodologies of enhanced multi-attributed adjacency graph (EMAAG) and feature-interaction feature graph (FIFG) for automatic extraction of primitive features and complex features of plastic parts, respectively, are presented. The test example shows that the methodologies developed can recognise various features of injection moulded parts successfully. [ABSTRACT FROM AUTHOR]

Particleboard panels are widely utilized as a raw material in the wood processing industry. It ends up as furniture, cabinets, and other industrial products. One of the problems particleboard mills face concerns the surface quality of their boards. As the demands of customers become more precise, very thin overlays are becoming more popular. Thus the problem of surface quality control and classification is clearly identified. In this paper, a particleboard surface-roughness classification system is modeled, simulated, and implemented. The particleboard model is based on the characterization of surface anomalies (pinholes. sander streaks, and grooves). Furthermore, an optical stylus surface-roughness measurement system is also modeled in order to determine whether it can be used w characterize a particleboard ‘on-ine.’ A classification algorithm is proposed to serve as an aid to the quality control operator. Simulation results are presented illustrating the change of surface roughness with increasing amounts of surface anomalies. A classification algorithm ix used to sort the simulated panels into different classes. A trial bench test using 225 panels is made to determine the applicability of this system to the industrial context. [ABSTRACT FROM AUTHOR]

Remanufacturing offers the potential for simultaneously recovering the economic value of manufactured components and improving the environment. Some design features make remanufacturing less expensive and/or increase the proportion of components that can be remanufactured. For example, sacrificial components can be used to protect key parts from wear. However, trade-offs are sometimes involved, and product designers need tools to support design for remanufacturing. This paper presents models for estimating the costs and environmental impacts of employing sacrificial components (cylinder liners) in engine blocks. These models are incorporated into a spreadsheet-based design decision tool. Three illustrative examples demonstrate that (1) remanufacturing lowers overall costs when two life cycles are considered. (2) sacrificial cylinder liners should be employed for small (2 L) engines, and their superiority increases with multiple remanufacturing cycles, and (3) for large engines (5.3 L) using cylinder liners is equally preferred to not using them, with respect to both overall cost and environmental impacts. [ABSTRACT FROM AUTHOR]

This paper presents a comparative study of the AC and MFDC resistance spot welding process. Both experiments and finite element simulation were conducted to compare the weld size and energy consumption. The experiments were performed on two identical spot welding machines, one with a single phase ac and the other with a mid-frequency DC weld control. The machines were instrumented such that both the primary and secondary voltage and current signals could be collected for energy calculation. The finite element simulation model was developed to understand the underlying mechanisms of the difference between the ac and MFDC processes. The effect of the current waveform was investigated by using the actual process measurements as an input to the simulation model. It is shown that the MFDC process generally produces larger welds than the AC process with the same root-mean-square welding current. However, this difference is more prominent when the welding current is relatively low. Overall, the AC welding process consumes more energy to make a same sized weld than the MFDC process. The larger the welding current is used, the less efficient the AC welding process will become. The differences between the two welding processes are caused by the contact resistance behavior and the electrical inductance in the AC welding process. [ABSTRACT FROM AUTHOR]

This paper deals with the conceptual design of a novel four-degree-of-freedom (dof) modularized robot which is composed of a 2-dof parallel mechanism plus a 2-dof rotating head attached to the moving platform. Patented with the name Bicept, the robot is the two-dimensional version of the Tricept robot and is designed as a reconfigurable module that can readily be integrated with 1-dof feed mechanism or a fixed base in order to form a set of reconfigurable robots with parallel-serial architecture. The dimensional synthesis of the 2-dof parallel mechanism as a component of the Bicept robot is also carried out by solving a one-dimensional nonlinear equation associated with the strut-length constraint. The dimensional parameters corresponding to various width-height ratios of the work space are obtained via examples. [ABSTRACT FROM AUTHOR]

In a number of manufacturing processes—tooling installation, calibration, and maintenance--guarantee the precision of fixtures and play important roles toward the overall quality of products. Recently, a new type of measurement equipment called a ‘laser tracker’ was developed and utilized for assembly fixture calibration to shorten calibration time and improve the accuracy of the currently used theodolite systems. Though calibration of the assembly fixture is critical for product quality, as such, calibration time creates a significant burden for productivity of multistation assembly processes. In order to shorten calibration lead time, the number of necessary setups, determined by visibility analysis, needs" to be minimized. This paper presents a screen space transformation-bated visibility analysis that allows minimizing the number of setups. The screen space transformation is applied to transform the visibility problem from three- to two-dimensional space, thus, efficiently solving the visibility problem. A case study illustrates the procedure and verifies the validity of the proposed methodology. This methodology can be applied not only for manufacturing processes, such us in-line fixture calibration, but also toward analysis and optimization of AGVs, robot navigation systems, and building security. [ABSTRACT FROM AUTHOR]

A fast temperature ramp of rapid thermal processing (RTP) with convective cooling used w shorten the cooling time for the wafer is presented in this paper. Based on thermal and stress analyses, the behavior of the highly coupled physics in RTP, such as radiative heat transfer, transient flow, and thermal stress is studied in detail. From simulation results of the flow field, a large recirculation cell between the wafer edge and the chamber wall is predicted and the effect of buoyancy on the behavior of the flow field is examined. Since the buoyancy-induced recirculation aggregates thermal nonuniformity due to edge effect. a guard ring is then suggested to be placed at the edge of the wafer to reduce the heat loss from the wafer edge and reflect the radiative energy back into the wafer during the cooling process. Furthermore, a large inlet gas mass flow rate is found to suppress the recirculation and shorten the cooling time. However, a fast convective cooling rate would result in a significant temperature difference between center and edge of the wafer, thus causing material failure due to an increase of thermal stresses. [ABSTRACT FROM AUTHOR]

A scratch inetersection based material removal mechanism for CMP processes ix proposed in this paper. The experimentally observed deformation pattern by SEM and the trends of the measured force profiles (Che et al., 2003) reveal that, for an isolated shallow scratch. the material is mainly plowed sideway along the track of the abrasive particle with no net material removal. However, it is observed that material is detached close to the intersection zone of two scratches. Motivated by this observation, it is speculated that the deformation mechanism changes from ploughing mode to shear-segmentation mode as the abrasive particle approaches the intersection of two scratches under small indentation depth for ductile metals. The proposed mechanistic material removal rate (MRR) model yields Preston constant similar to those observed experimentally for CMP processes. The proposed model also reveals that the nature of the slurry-pad interaction mechanism, and its associated force partitioning mechanism, is important for determining the variation of MRR with particle size and concentration. It is observed that under relatively soft pads, small particles and low particle concentration, the pad undergoes local deformation, yielding an increased MRR with increasing particle size and concentration. At the other extreme, the intact walls of the surface cells and the connecting cell walls between the surface pores deform globally, resembling a beam or a plate, and a decreasing trend in MRR is observed with increasing particle size and concentration. The predicted MRR trends are compared to existing experimental observations. [ABSTRACT FROM AUTHOR]

This paper reports an integrated approach for jointly solving the process selection, machining parameter selection, and tolerance design problems to avoid inconsistent and infeasible decisions. The integrated problem is formulated as a bicriterion model to handle both tangible and intangible costs. The model is solved using a modified Chebyshev goal programming method to achieve a preferred compromise between the two conflicting and noncommensurable criteria. Examples are provided to illustrate the application of the model and the solution procedure. The results show that the decisions on process selection, machining parameter selections, and tolerance design tan be made simultaneously with the model. [ABSTRACT FROM AUTHOR]

Variation propagation modeling has been proved to be an effective way for variation reduction and design synthesis in multi-operational manufacturing processes. However, previously developed approaches for machining princesses did not directly model the process physics regarding how fixture, and datum, and machine tool errors generate the same pattern on part features. Consequently it is difficult to distinguish error sources at each operation. This paper formulates the variation propagation model using the proposed equivalent fixture error concept. With this concept, datum error and machine tool error are transformed to equivalent fixture locator errors at each operation. As a result, error sources can be grouped and root cause identification can be conducted in a sequential manner. The case studies demonstrate the model validity through a real cutting experiment and model advantage in measurement reduction for root cause identification. [ABSTRACT FROM AUTHOR]

This paper proposes an analytical approach to detect depth-of-cut variations based on the cutting-force shape characteristics in end milling. Cutting forces of a single-flute end mill are analyzed and classified into three types according to their shape characteristics. Cutting forces of a multiple-flute end mill are then classified by considering both the cutting types of the corresponding single-flute end mill and the degree of overlap the successive flutes in the cut. Force indices are extracted from the cutting forces and depth-of-cut variations are detected based on the changes of the force shape characteristics via the force indices in an end-milling process. The detection methodology is validated through cutting experiments. [ABSTRACT FROM AUTHOR]

This paper presents a systematic finite element model to predict the fixture unit stiffness by introducing nonlinear contact elements on the contact surface between fixture components. The contact element includes three independent springs: two in tangential directions and one in the normal direction of the contact surface. Strong nonlinearity is caused by possible separation and sliding between two fixture components. The problem is formulated by the penalty function method and is solved by the Newton­Raphson procedure. The model was validated by two cases of analysis of a linear cantilever beam and a simple fixture unit with two components. The results are in agreement with the corresponding analytical solution of beams and the previous experimental results for fixture in the literature. [ABSTRACT FROM AUTHOR]

This paper proposes a method by which material in- homogeneity may be taken into account in a reliability calculation. The method employs Monte-Carlo simulation; and introduces a material strength index, and a standard deviation of material strength to model the variation in the strength of a component throughout its volume. The method is compared to conventional load-strength interference theory. The results are identical for the case of homogeneous material, but reliability is shown to reduce for the same load as the component volume increases. The case of a tensile bar is used to explore the variation of reliability with component volume. [ABSTRACT FROM AUTHOR]

This paper reviews the new concept "microfactory" and related developments. Machined parts are becoming progressively smaller; so production machinery that remains a conventional size is often inappropriate for such products. The term "microfactory" represents an entirely new approach to design and manufacture that minimizes production systems to match the size of the parts they produce. It leads to conservation of space and energy, and the reduction of investment and operational costs, as well as the reduction of emissions and the load on operators. Furthermore, it provides a system with dynamic reconfigurability, aiming at a light and agile manufacturing system optimized for current manufacturing needs in a borderless and highly competitive market. In Japan, research institutes, research consortia, and the private sec- tor have carried out targeted research and development aimed at this concept for over a decade. Some systems are past the research stage and in daily use. Outside Japan, the philosophy and advantages of microfactory have reached an appreciative audience in the U.S., Europe, and Asia. Microfactory is at the cutting edge of competitive manufacturing in the 21st century, ushering in a multidimensional paradigm shift. Here we also briefly examine some future tasks. [ABSTRACT FROM AUTHOR]

Capacitive displacement sensors are widely used in precision manufacturing and metrology because they measure displacements with nanometer resolution. Prior literature usually treats capacitive sensors consisting of electrodes arranged as parallel plates. in this work, the target electrode is spherical, which is common in machine tool metrology, spindle metrology, and the measurement of sphericity. The capacitance due to a gap between flat and spherical electrodes is less than that of two flat electrodes, which causes four effects. As the diameter of the target electrode is reduced, the sensitivity increases, the sensing range decreases, the sensing range shifts toward the target, and the sensor becomes nonlinear This paper demonstrates and quantifies these effects for a representative capacitive sensor using finite element analysis and experimental testing. For larger spheres, the effects are correctible with apparent sensitivities, but measurements with the smallest spheres become increasingly nonlinear and inaccurate. [ABSTRACT FROM AUTHOR]

Nickel and nickel-alloy microparts sized on the order of 5-1000 microns have been imaged in three dimensions using a new microscopic technique, Digital Volumetric Imaging (DVI). The gears were fabricated using Sandia National Laboratories' LIGA technology (lithography, molding, and electroplating). The images were taken on a microscope built by Resolution Sciences Corporation by slicing the gear into one-micron thin slices, photographing each slice, and then reconstructing the image with software. The images were matched to the original CAD (computer aided design) model, allowing LIGA designers, for the first time, to see visually how much deviation from the design is induced by the manufacturing process. Calibration was done by imaging brass ball bearings and matching them to the CAD model of a sphere. A major advantage of DVI over scanning techniques is that internal defects can be imaged to very high resolution. In order to perform the metrology operations on the microcomponents, high-speed and high-precision algorithms are developed for coordinate metrology. The algorithms are based on a least-squares approach to data registration the {X, Y,Z} point clouds generated from the component surface onto a target geometry defined in a CAD model. Both primitive geometric element analyses as well as an overall comparison of the pan geometry are discussed. initial results of the micromeasurements are presented in the paper. [ABSTRACT FROM AUTHOR]

This paper reports on nanosurface fabrication of hard brittle materials by structured diamond tool imprinting. Ultrafine structured surfaces were fabricated on soda glass, firelite glass, quartz glass, quartz wafer and silicon. A specially designed and developed nanoindentation tester and a structured diamond tool machined by Focused Jon Beam (FIB) are used for the generation of such surfaces. Imprinted marks and the ultrafine structures are analyzed for their geometrical shape and accuracy. Load-depth analysis on the formed surfaces was carried out. Critical depth, at which ductile-to-brittle transition in deformation occurs, was assessed for the hard brittle materials. Limits of ductile mode indentation for hard brittle materials were discussed in detail. Variation in the depth of structures in an imprinted mark was studied. [ABSTRACT FROM AUTHOR]

This paper examines the surface generation process in the micro-endmilling of both single-phase and multiphase workpiece materials. We used 508 µm dia endmills with edge radii of 2 and 5 ,am to machine slots in ferrite, pearlite, and two ductile iron materials at feed rates ranging from 0.25 to 3.0 µm/flute. A surface generation model to predict the surface roughness for the slot floor centerline is then developed based on the minimum chip thickness concept The minimum chip thickness values were found through finite element simulations for the ferrite and pearlite materials. The model is shown to accurately predict the surface roughness for single-phase materials, viz., ferrite and pearlite. Two phenomena were found to combine to generate an optimal feed rate for the surface generation of single-phase materials: (i) the geometric effect of the tool and process geometry and (ii) the minimum chip thickness effect The surface roughness measurements for the ductile iron workpieces indicate that the micromilling surface generation process for multiphase workpiece materials is also affected by the interrupted chip-formation process as the cutting edge moves between phases resulting in burrs at the phase boundaries and the associated increases in surface roughness. [ABSTRACT FROM AUTHOR]

In Part II of this paper, a cutting force model for the micro-endmilling process is developed. This model incorporates the minimum chip thickness concept in order to predict the effects of the cutter edge radius on the cutting forces. A new chip thickness computation algorithm is developed to include the minimum chip thickness effect. A slip-line plasticity force model is used to predict the force when the chip thickness is greater than the minimum chip thickness, and an elastic deformation force model is employed when the chip thickness is less than the minimum chip thickness. Orthogonal, micro structure-level finite element simulations are used to calibrate the parameters of the force models for the primary metallurgical phases, ferrite and pearlite, of multiphase ductile iron workpieces. The model is able to predict the magnitudes of the forces for both the ferrite and pearlite workpieces as well as for the ductile iron workpieces within 20%. [ABSTRACT FROM AUTHOR]