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The article presents calendar of events related to mechanical engineering for 2006. The 19th International Congress & Exhibition on Condition Monitoring and Diagnostic Engineering Management will be on June 12 and 15. The 10th International Conference on Electrorheological Fluids and Magnetorheological Suspensions will take place in June 18 to 22. The 7th International Conference on Vibration Measurements by Laser Techniques-Advances and Applications & Short Course. The 13th International Congress on Sound and Vibration will be on July 2 to 6. The 16th European Conference on Fracture will be on July 3 to 7.

This document is a summary of an article titled "Industry 4.0, Artificial Intelligence, and Mechanical Engineering towards Industry 5.0" published in the Journal of Engineering, Project & Production Management. The article discusses the role of Industry 4.0, artificial intelligence, and mechanical engineering in the sustainability of industries in the future. It highlights the transition to the Industry 5.0 paradigm, which combines technology with human-centered approaches for the benefit of the workforce and society. The article also includes summaries of several papers that explore various aspects of this transitional paradigm, such as renewable energy sources, heat transfer, machining hard materials, complex metamaterial structures, data logging and analysis in the Internet of Things, internet financing, urban garden designs, risk management in construction projects, and the application of machine learning algorithms in civil engineering. The author expresses gratitude to the members of the International Scientific Committees for their contribution to the peer-review process and hopes that the papers will be valuable to researchers and practitioners in the field. [Extracted from the article]

The paper describes an effort to improve the industrial engineering course knowledge of a group of mechanical engineering students who are in 4th semester. The purpose of the research was to evaluate the efficacy of the "out of classroom" teaching strategy in the context of skill sets appropriate for the business and industry domains. The main emphasis is given on "Value Engineering" and "Value Analysis" techniques. The students were divided into group of clusters and they have been assigned in various projects by subject faculty which contains deferent levels to complete. The results show that the learning strategy can improve management, business, and engineering abilities, and that it has the capacity to do so in a single semester of study. [ABSTRACT FROM AUTHOR]

In this paper, a novel model for a deteriorating manufacturing system is analysed, considering repairs and overhauls of random durations. The machine manufactures one product and the model is further complicated because the quality of the parts’ produced deteriorates according to the wear of the machine and human interventions. When a breakdown occurs, either a repair or an overhaul is performed. The machine is restored to as-good-as-new conditions if the overhaul is selected, and conversely, its condition deteriorates following repairs. Multiple operational states are considered to define an ageing process. The decision variables of the model are the production rate and the repair/overhaul switching strategy. This paper provides new insights to this research area by considering the simultaneous production and repair/overhaul control policy under the effect of deteriorations. The optimal decision policy minimises the total incurred cost comprising the inventory, backlog, repair and overhaul costs over an infinite planning horizon. Our paper differs from other research projects in its consideration of the machine’s history, defined by the number of repairs and multiple operational states. A numerical example is given to illustrate the proposed approach and a sensitivity analysis has been conducted to confirm the structure of the obtained control policies. [ABSTRACT FROM PUBLISHER]

Planning in mechanical engineering is a key factor for a successful product development process. Especially, when it comes to producing machines, planning drastically reduces the risk of failures in either processes or parts. The commissioning process is mainly focusing on adjusting and testing. Thus, commissioning is the process where most of the failures are detected. On the one hand, in literature, the planning of processes has mainly focused on the optimisation of the planned duration of a production process. Durations of errors in processes and possible effects on other processes have not been considered in the literature. On the other hand, risk analyses mainly focus on the minimisation of errors in either processes or products. The goal of this paper is to develop an applicable methodology for the combination of an optimisation of the risk and the duration of a commissioning process in mechanical engineering. The focus is to analyse the planning of a commissioning process and combine it with a methodology to optimise risks and durations. Furthermore, the method is designed to be applicable in all areas of mechanical engineering. The method is validated at the commissioning of special machinery and during ramp-up processes and has shown a possible time reduction of about 40% without increasing the risks of failures. [ABSTRACT FROM AUTHOR]

This paper presents a feedback adjustment rule for discrete-part manufacturing processes that experience errors at the setup operation which are not directly observable due to part-to-part variability and measurement error. In contrast to previous work on setup adjustment, the off-target cost function of the process is not symmetric around its target. Two asymmetric cost functions—constant and quadratic functions—are considered in this paper. By introducing a bias term in the feedback adjustment rule, the process quality characteristic converges to the optimal steady-state target from the lower cost side of the cost function. This minimizes the off-target loss incurred during the transient phase of adjustment. A machining application is used to illustrate the proposed adjustment procedure and to demonstrate the savings generated by the proposed feedback adjustment rule compared to an adjustment rule due to Grubbs and to an integral controller. It is shown that the advantage of the proposed rule is significant when the cost of the items is high, items are produced in small lot sizes and the asymmetry of the cost function is large. [ABSTRACT FROM AUTHOR]

3D printers are well known and widespread in several fields, such as architecture, design, mechanical and industrial engineering, constructions, medical, food, clothing, etc. The 3D printer has become a device almost as familiar as the paper printer. The technologies used for 3D printing are diverse and adapted to the functional requirements of the printed product as well as to the material used for printing correlated with the necessary costs. Printers with FDM (Fused Deposition Modeling) technology are an affordable segment in terms of both price and use, making this type of printer very popular with regular consumers, who use it most often to replace common worn or damaged components. This study focuses on the possibility of printing Metric type threaded surfaces on FDM type printers. The study presents experimental results and conclusions regarding the attempt to obtain these surfaces on printers and includes some recommendations towards printing such parts. [ABSTRACT FROM AUTHOR]

Copyright of Nova Scientia is the property of Nova Scientia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A novel algorithm for solving the classic Stefan problem is proposed in the paper. Instead of front tracking, we preset the moving interface locations and use these location coordinates as the grid points to find out the arrival time of moving interface respectively. Through this approach, the difficulty in mesh generation can be avoided completely. The simulation shows the numerical result is well coincident with the exact solution, implying the new approach performes well in solving this problem. [ABSTRACT FROM AUTHOR]

This paper proposes the use of the Lego® Serious Play® (LSP) methodology as a facilitating tool for the introduction of competences for Industrial Risk Prevention by engineering students from the industrial branch (electrical, electronic, mechanical and technological engineering), presenting the results obtained in the Universities of Cadiz and Seville in the academic years 2017-2019. Current Spanish legislation does not reserve any special legal attribution, nor does it require specific competence in occupational risk prevention for the regulated profession of a technical industrial engineer (Order CIN 351:2009), and only does so in a generic way for that of an industrial engineer (Order CIN 311:2009). However, these universities consider the training in occupational health and safety for these future graduates as an essential objective in order to develop them for their careers in the industry. The approach is based on a series of challenges proposed (risk assessments, safety inspections, accident investigations and fire protection measures, among others), thanks to the use of "gamification" dynamics with Lego® Serious Play®. In order to carry the training out, a set of specific variables (industrial sector, legal and regulatory framework, business organization and production system), and transversal ones (leadership, teamwork, critical thinking and communication), are incorporated. Through group models, it is possible to identify dangerous situations, establish causes, share and discuss alternative proposals and analyze the economic, environmental and organizational impact of the technical solutions studied, as well as take the appropriate decisions, in a creative, stimulating, inclusive and innovative context. In this way, the theoretical knowledge which is acquired is applied to improve safety and health at work and foster the prevention of occupational risks, promoting the commitment, effort, motivation and proactive participation of the student teams. [ABSTRACT FROM AUTHOR]

This paper takes an empirical look into industrial design in process and metal industries. The data are based on a case study of an industrial design pilot project at a company that is a market leader in mineral processing systems. In the paper, the overall structure of the project is outlined and aspects of design work are addressed through detailed analysis of interactions between the participants. In addition, the role of visualizations and the nature of design problems are examined. The conclusions of the paper include implications for the organization of industrial design projects. In addition, general notes are made about the nature of industrial design within the company—and technology intensive areas in general. [ABSTRACT FROM AUTHOR]

To improve the total product development process, engineering and production planning processes have to be integrated into one overall workflow. These processes are performed in different application systems, partially with workflow support (e.g. Enovia Workflow) and partially without (e.g. Manufacturing Hub). In order to achieve higher process reliability and performance as well as continuous information flow, the overall workflow shall be controlled by a general-purpose workflow management system (WfMS). Thus, the overall workflow may serve as a base for monitoring, reporting, and process visualization with the goal of managing the workflow execution. In this paper, we present a general approach that realizes the control of the overall workflow in conjunction with the execution of local workflow fragments by heterogeneous application systems. This approach is used to integrate the Dassault Systemes products Enovia V5 and Manufacturing Hub into an overall workflow controlled by the IBM WBI Workflow component. The paper describes how such an integration can be realized for these systems. [ABSTRACT FROM AUTHOR]

This paper provides a brief discussion on flexibility concepts in manufacturing. It emphasizes that flexibility measurements in a manufacturing system should be studied under dynamically changing environments rather than static ones. The approaches for assessing two major flexibility types, machine flexibility and product mix flexibility response, are presented. The machine flexibility model is based on machine-operation efficiency. The product mix flexibility response model is based on the difference between products in terms of tooling requirements, the number of operations that a machine can perform and the efficiency of different machines. [ABSTRACT FROM AUTHOR]

Sculptured or free-form surfaces are widely used in many fields with extensive applications. Once such surfaces are manufactured, surface inspection compares the manufactured surfaces with the surface design specifications to verify conformance. Although significant research and development efforts have been devoted to the design and manufacturing of products consisting of partial or sole free-form surfaces, the inspection of these surfaces is still a difficult task. For many engineering applications, a free-form surface is assigned a profile tolerance with reference to design datums for assembly, functionality and other manufacturing requirements. The paper discusses developments of surface inspection techniques for profile tolerance of free-form surfaces. The concept of datum direction frame is proposed to find the transformation information that localizes measurement data to design model. The technique consists of two major steps: localization of measurement data to the design system, based on the datum reference information; and further localization based on the information from free-form surfaces. Testing examples were carried out to validate the developed techniques. The new method does not need corresponding points from the datums of the design model and measured surfaces. Therefore, it is simpler, yet more robust. It can also be used conveniently in manufacturing processes. [ABSTRACT FROM AUTHOR]

In this article, improvements in assembly workplace layouts in an industrial context are investigated to enhance productivity and efficiency. The installation of the Cleaner M300 device is focused on, existing layout challenges are identified, and targeted improvements are proposed. Data collection, analysis, and real-world experimentation are employed to evaluate current workplace conditions and potential enhancements, including material flow dynamics and transport cart utilization. Proposed solutions are aimed at streamlining assembly processes, minimizing material transportation time, and boosting operational efficiency. The effectiveness of these improvements is validated through qualitative feedback from workers and supervisors. The importance of improving workplace design to enhance manufacturing operations, increase productivity, and improve transport efficiency is underscored by the study. [ABSTRACT FROM AUTHOR]

In the Fall of 2016, the Department of Engineering Technology and Industrial Distribution (ETID) at Texas A&M University opened a new degree program entitled Multidisciplinary Engineering Technology (MXET). This new program is structured to give students a strong underpinning in both the electronics and mechanical engineering technology disciplines. The curriculum then culminates in a 29-hour focus area that customizes the degree plan for a particular area of the job market. Currently, the degree has a single focus area in Mechatronics, preparing students for careers in the design, development, implementation, and support of electromechanical systems that are controlled through embedded hardware and software. The MXET degree is now being expanded to include new additional focus areas. The first one of these areas is STEM (science, technology, engineering, and mathematics) Teacher Preparation. In collaboration with the College of Education, a MXET focus area is being customized to produce graduates who can sit for their Mathematics/Science/ Engineering certification and who can teach at the junior high and high school levels. This new focus will be available starting in the Fall of 2017. The second new focus area is in Entrepreneurial Product Development. This specialization is for the unique student who is interested in starting a technology/ product-based company, and the goal is to allow the student to incubate the new company while attending courses and finishing his/her degree. This paper will discuss these two new focus areas in detail and will also discuss the more general process of identifying new focus areas for MXET and using the program to respond more rapidly to the needs of industry, the state, and the nation. [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]

This paper presents a discretization methodology applied to the NBV (Next Best View) problem, which consists of determining the heuristical best position of the next scan. This new methodology is a hybrid process between a homogenous voxelization and an octree structure that preserves the advantages of both methods. An octree structure is not directly applicable to the NBV problem: as the point cloud grows with every successive scanning, the limits and position of the discretization, octree structure must coincide, in order to transfer the information from one scan to the next. This problem is solved by applying a first coarse voxelization, followed by the division of each voxel in an octree structure. In addition, a previous methodology for solving the NBV problem has been adapted to make use of this novel approach. Results show that the new method is three times faster than the homogenous voxelization for a maximum resolution of 0.2m. For this target resolution of 0.2m, the number of voxels/octants in the discretization is reduced approximately by a 400%, from 35.360 to 8.937 for the study case presented. [ABSTRACT FROM AUTHOR]

Copyright of International Journal of Production Research is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents a new model for workforce allocation in labour-intensive industries. In such industries where production processes mostly include manual assembly operations, performance is highly influenced by the availability of skilled workers. Sudden unavailability of skilled labour has significant adverse effects on production. Furthermore, as competition intensifies, production becomes more sensitive to changing market demands. Such disturbances can be attenuated by introducing flexibility in the production planning process. Workforce allocation plays a significant role in the planning process. Thus, this paper focuses on workforce allocation, and a support system is developed from the concepts of holonic manufacturing systems and PROSA reference architecture. The system was designed in unified modelling language and was tested using an object-oriented software developed in C++. The use of the holonic methodology to develop the system has helped to identify the shortfalls of the conventional method adopted in industry and develop algorithms to improve the workforce allocation process. The proposed system was simulated using production data from a computer manufacturer case study. The paper then presents a comparison of the factory’s conventional method of workforce allocation with the proposed holonic workforce allocation system. The results suggest an improved manufacturing throughput performance. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Mechanical Engineering / Strojniški Vestnik is the property of University of Ljubljana, Faculty of Mechanical Engineering, Journal of Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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]

This paper presents a new approach to multiobjective optimization based on the principles of probabilistic uncertainty analysis. At the core of this approach is an efficient nonlinear multiobjective optimization algorithm, Minimizing Number of Single Objective Optimization Problems (MINSOOP), to generate a true representation of the whole Pareto surface. Results show that the computational savings of this new algorithm versus the traditional constraint method increase dramatically when the number of objectives increases. A real world case study of multiobjective optimal design of a best available control technology for Nitrogen Oxides (NOx) and Sulfur Oxides (SOx) reduction illustrates the usefulness of this approach. [ABSTRACT FROM AUTHOR]

With the continuous improvement of computational performance, vehicle structural design has been addressed using computational methods, resulting in more efficient development of new vehicles. Most simulation-based optimization approaches generate deterministic optimal designs without considering variability effects in modeling, simulation, and/or manufacturing. One of the main reasons for this omission is due to the fact that the computing time of a single crash analysis for vehicle structural design still requires significant computing time using a state-of-the-art computer. This calls for the development and implementation of an efficient optimization under uncertainty method. In this paper, a new integrated stochastic optimization method, which combines the advantages of metamodeling techniques and Better Optimization of Nonlinear Uncertain Systems (BONUS), is developed for vehicle side impact design. Nonlinear metamodels are built by using a stepwise regression method to replace the expensive computational model and BONUS is employed to obtain optimal designs under uncertainty. A benchmark problem for vehicle safety design is used to demonstrate the method. The main goal of this case study is to maintain or enhance the vehicle side impact test performance while minimizing the vehicle weight under various uncertainties. [ABSTRACT FROM AUTHOR]

3D inspection process is getting more and more interest for manufacturing industries as it helps to carefully check the expected quality of the released products. Much more attention is oriented to optical devices able to quickly capture the whole shape of the product providing many useful information on the process variability and the deliverability of the key characteristics linked to the quality of the product/process. Although the optical control of 3D scanners is mature enough, many factors may influence the quality of the scanned data. These factors may be strictly related to internal elements to the acquisition device, such as scanner resolution and accuracy, and external to it, such as proper selection of scanning parameters, ambient lighting and characteristics of the object surface being scanned (e.g. surface colour, glossiness, roughness, shape), as well as the sensor-to-surface relative position. For the 3D laser-based scanners, the most common on the market, it would be of great industrial interest to study some scanning factors mainly affecting the quality of the 3D surface acquisitions and provide users with guidelines in order to correctly set them so to increase the massive usage of these systems in the product inspection activities. In this context, by using a commercial triangulation 3D laser scanner, the effects of some scanning factors that may affect the measurement process were analysed in the present paper. Working on a sheet metal test part, more complex than the ones commonly used in laboratory and documented in the literature, the scanner-to-object relative orientation and the ambient lighting, as well as an internal scanner parameter, were tested. Through a Design of Experiments (DoE) approach, and setting root mean square error (RMSE) as response function, the outcomes of the tests mainly pointed out that the scanner-to-object relative orientation as well as its position within the field of view of the measurement device are the key factors mostly influencing the accuracy of the measurement process. [ABSTRACT FROM AUTHOR]

With growing worldwide interest in commercial, scientific, and military issues associated with both oceans and shallow waters, there has been a corresponding growth in demand for the development of unmanned surface vehicles (USVs) with advanced guidance, navigation and control (GNC) capabilities. This paper presents a comprehensive literature review of recent progress in USVs development. The paper first provides an overview of both historical and recent USVs development, along with some fundamental definitions. Next, existing USVs GNC approaches are outlined and classified according to various criteria, such as their applications, methodologies, and challenges. Finally, more general challenges and future directions of USVs towards more practical GNC capabilities are highlighted. [ABSTRACT FROM AUTHOR]

The paper brings forward the experimental cutting trials of a series of dead rocks found in Husnicioara quarry belonging to The National Company of Lignite "Oltenia". These experimental trials were carried out on significant sterile rocks of the aforementioned quarry on a bench conceived and realised in the "Mining Machines and Equipment" Laboratory of the Department of Mechanical and Industrial Engineering and Transports. The experimental trials were carried out on sterile samples taken from the topsoil stripping of the layers of lignite which is surface mined in the aforementioned quarry. [ABSTRACT FROM AUTHOR]

The experience presented is part of the teaching of two subjects of the Mechanics discipline: Continuum Mechanics and Strength of Materials, in the field of Mechanical and Industrial Engineering. In the bachelor's degree at the ETSEIB-UPC, the first semester of the third academic year is devoted to Continuum Mechanics and the second one to Strength of Materials. Both subjects integrate theory and practice: applications, lab and coursework. The article focuses on the coursework or also named course project, which consists of designing/optimizing, analysing, manufacturing and testing a mechanical/structural element subject to stresses and strains. This paper aims at showing the benefits of combining practice, theory, simulation and experimentation, as well as some of the limitations and difficulties encountered in its implementation, such as the evaluation of the degree of involvement of each team member and the lack of correlation between the mark of the coursework and examinations' scores. An important conclusion is that students enjoy the project, get deeply involved and work hard, making the subject more attractive. [ABSTRACT FROM AUTHOR]

Business process engineering and modelling is an important practical activity, presently based on a variety of methodologies. These are practically derived methods, grounded in concepts such as "action", "event", "process" and "model", which can vary according to methodology. In this paper, we formalise these notions of business process, actions and business models, by relating them to well-established theories of time and temporal activity. The ontology of the terms employed in business process engineering is discussed, and formal definitions of the main terms are given. The term "temporal model" of a business process is introduced, and a formal definition of a sub-process is given with relation to the temporal model. A sub-process can be viewed as a module of a business process which can be replaced or altered without affecting the rest of the process. It is shown that existing business process models using business process modelling can be given a logical foundation based on formal temporal theory. [ABSTRACT FROM AUTHOR]

The paper explains the basic aspects of designing controllers for an industrial robot control. Industrial robots are basically mechanical devices which, to a certain degree, replicate human motions. They are used whenever there is a need to reduce the danger to a human, provide more strength or accuracy than a human, or when continuous operation is required. Most industrial robots are stationary, but some move throughout the workplace delivering materials and supplies. While we have the technical ability to produce human robots, industrial robots are actually quite simple devices. Motions that we take for granted–picking up a something from the table, for instance–are considerably more difficult for a robot. Its mains characteristics of operation, degrees of freedom, etc. They are solved and the calculations developed to obtain the kinematics and dynamics. The accomplished test to each servomotors and the research about its operation. Basicaly all industrial robot have a similarly control, because have a similarly actions. [ABSTRACT FROM AUTHOR]

More than 20 years parallel robots attract the interest of the scientific community and in many applicative domains like, production of motion generators, machine tools, precision positioning devices, medical equipment, pick and place machines, etc., where their potential advantages (high accuracy, rigidity, speed, acceleration and load carrying capability) could be very useful. The objective of this paper is to notify some of the open questions in parallel robotics, which is limitation factor of wider practical application of this type of robots. [ABSTRACT FROM AUTHOR]

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]

Abstract: The paper describes a framework for novelty creation, based in complexity, and how it enables the management for novelty in manufacturing systems. The paper''s central thesis is that complexity should not be eliminated but nurtured. The human role is focused on. The paper evaluates how the creation of novelty is recognized in existing MS approaches such as Collaborative Design, Complexity, Emergent Synthesis, and Networked Organizations. A complexity framework is proposed to develop a chaordic manufacturing system. [Copyright &y& Elsevier]

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]

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]

This paper presents an analytical approach for performing fault tree analysis (FTA) with stochastic self-loop events. The proposed approach uses the flow-graph concept, and moment generating function (MGF) to develop a new stochastic FTA model for computing the probability, mean time to occurrence, and standard deviation time to occurrence of the top event The application of the method is demonstrated by solving one example. [ABSTRACT FROM AUTHOR]

Accurate knowledge of the effect of parameter uncertainty on process design and operation is essential for optimal and feasible operation of a process plant. Existing approaches dealing with uncertainty in the design and process operations level assume the existence of a well defined model to represent process behavior and in almost all cases convexity of the involved equations. However, most of the realistic case studies cannot be described by well characterised models. Thus, a new approach is presented in this paper based on the idea of High Dimensional Model Reduction technique which utilize a reduced number of model runs to build an uncertainty propagation model that expresses process feasibility. Building on this idea a systematic iterative procedure is developed for design under uncertainty with a unique characteristic of providing parametric expression of the optimal objective with respect to uncertain parameters. The proposed approach treats the system as a black box since it does not rely on the nature of the mathematical model of the process, as is illustrated through a number of examples. [ABSTRACT FROM AUTHOR]

In research studies of conveyor-based work, the work-task is often chosen on the basis of experimental convenience. This paper, however, shows that the task itself could be an important parameter in such studies. It is shown that if a work-task is split into two smaller tasks, the relative variability of at least one of the sub-groups must be greater than that of the parent group. This is likely to lead to a decrease in the overall performance of the system. SUMMARY. [ABSTRACT FROM AUTHOR]

Lot streaming is the process of splitting a job or lot to allow overlapping between successive operations in a multistage production system. This use of transfer lots usually results in a substantially shorter makespan for the corresponding schedule. In this paper, we study the discrete lot streaming problem for a single job in no-wait flow shops. We present a new linear programming formulation for the problem. We show that the optimal solutions are the same for the m x 2 case with or without no-wait constraints. We also present a fast, polynomial-time solution method for this case. For the general case, we prove that any solution which is 'close' to the continuous optimal solution will be a good approximation for the discrete problem. This property allows us to present two quickly obtainable approximations of very good quality. [ABSTRACT FROM AUTHOR]