Mechanical Engineering Design Research Articles

The Design Exemplar: A New Data Structure for Embodiment Design Automation

A key issue in developing new intelligent computer aided design and manufacturing tools (CAD/CAM) is knowledge representation. Engineering knowledge has been represented in many forms, such as rule sets, design procedures, features, frames, and semantic networks. Some of these are domain dependent, some are query dependent, and some require specialized inferencing engines or solving algorithms, thus providing a severe limitation for exchange and re-use of design knowledge. A standard representation structure that is capable of encapsulating different types of knowledge would be a useful tool. The design exemplar provides a standard representation of mechanical engineering design problem knowledge based upon a canonically derived set of entities and relationships. The data structure of the design exemplar facilitates four basic design tasks: pattern matching, property extraction, design validation, and change propagation. This paper shows that it is possible to map the design exemplar to other representations (procedures, rules, and features). The concept of integrating atomic design exemplars into composite networks for performing complex design tasks is also introduced as a tool for developing and applying the design exemplar in engineering design automation.

Editorial

A collaboration of five international conferences and two symposia devoted to mechanical engineering design research form the 2004 ASME Design Engineering Technical Conferences and Computers and Information in Engineering Conference that will take place in Salt Lake City, Utah, September 28 through October 2. At the age of 54 the Biennial Mechanism and Robotics Conference, meeting every two years since its inception at Purdue University in 1950, is solidly middle aged. The youngest is the Design for Manufacturing Conference which met for the first time at the 1996 DETC that I had the pleasure of hosting in Irvine, California. The conferences on design automation, computers and information in engineering, and design theory and methodology round out the list with ages of 27, 23 and 15 years, respectively. This event also includes two symposia, which in time may become conferences on their own. The symposium on International Issues on Engineering Design is meeting for a second time and includes the topic of “design engineering in service to humanity,” an explicit expression of what I would expect we all feel is the role of the technology that we spend so much time studying. The topics in the newest program, the Symposium on Integration of Materials Microstructure and Chemistry in Multidisciplinary Design Optimization for which the acronym IMMCMDO has been shortened to IMDO, illustrate that specification of material mixtures, assemblies, and microstructure are now within the scope of the mechanical designer. Central to these conferences is, of course, the presentation of reviewed papers and their collection into proceedings, and perhaps journal publication. For 21 years the final steps of publication of our papers have involved the name Ray Ramonas. I know him as the individual who assists me in organizing papers for each issue of the Journal of Mechanical Design and who prods me to complete an editorial on time. He is the ASME Production Editor and he retires with this issue. I share the sentiments of ASME’s Ms. Cynthia Clark, Managing Editor, Technical Publishing, who writes “Ray is the consummate publishing professional: he takes great pride in his work and has developed excellent relationships with all who have crossed his path. Authors, editors, vendors, and, most of all, colleagues will truly miss him.”

Issues in mechanical engineering design management

The Virtual Parts Engineering Research Center (VPERC), funded by the Army Research Office, focuses on building frameworks, tools, and technologies for making engineered systems sustainable and maintainable thanks to a virtual engineering environment intended to transform the engineering process, thus supporting extremely fast turnaround times for urgent part supply needs. One of its key research thrusts is data management targeted for the design process. The invitational VPERC workshop held at Arizona State University in June 2003, involved 38 participants from academia, governmental institutions and industry who discussed legacy systems engineering. This paper presents the data management needs to support mechanical engineering design as they were discussed at the meeting.

離散化構造要素を用いたトポロジー最適化 : 固有振動数最大化を目的とした場合(S54-1 設計支援手法・CAD/CAE(1),S54 設計支援手法・CAD/CAE)

This paper discusses a structural topology optimization method based on frame elements. The purpose of this method is to support decision-making as engineers work to obtain innovative designs and evaluate mechanical design details at the conceptual design phase for mechanical structures such as automotive bodies and machine tools. When developing mechanical products, enrichment of the conceptual phase is an important issue. At the conceptual design phase, basic structural and mechanical design features that directly affect product performance are decided. Especially, vibration characteristic is concerned with product performances such as durability, and one of the most important features. So, in this paper, we present an eigen value maximize topology optimization method based on discrete and function-oriented elements such as frame, panel and spring elements, and sequential convex programming. In addition, examples are provided to show the utility of the methodology presented here for mechanical design engineers.

Topology Optimization Using Structural Discrete Elements

Computer Aided Engineering (CAE) has been successfully utilized in mechanical industries, but few CAE tools that include structural optimization can be utilized at the conceptual design phase, since the development of such tools has been based on continuum mechanics that limit the provision of useful design suggestions at this phase. In order to mitigate this problem, a new type of CAE based on classical structural mechanics, First Order Analysis (FOA), is proposed. In this paper, we present a topology optimization method that corresponds to FOA concepts. This optimization method is constructed, based on discrete and function-oriented elements such as frame, panel and spring elements, and sequential convex programming. In addition, examples are provided to show the utility of the methodology presented here for mechanical design engineers.

Theory of Machines and Mechanisms

Theory of Mechanisms by John J. Uicker, Gordon R. Pennock and Joseph E. Shigley, 3rd Edition. Oxford Press, 2003The scholarship of the late Joseph Shigley continues to influence mechanical design education almost a decade after his death in 1994 through the publication of new editions of his books Theory of Machines and Mechanisms (Oxford Press) with Profs. Uicker and Pennock, and his Mechanical Engineering Design (McGraw-Hill) with Prof. Mischke. The Theory of Machines and Mechanisms traces itself to the integration of Prof. Shigley’s Kinematic Analysis of Mechanisms and Dynamic Analysis of Machines into the single book Theory of Machines in 1961. John Uicker worked with Prof. Shigley on the 1995 second edition that included the analysis of spatial mechanisms and robots using vector formulations adapted for numerical computation. For this third edition, Gordon Pennock joins Prof. Uicker to provide an impressive new look to this classic text. The book is divided into three basic parts: kinematics and mechanisms, the design of mechanisms, and dynamics of machines. In the first part, the focus is on the analysis of mechanical movement, and I like the vector and matrix formulation that includes kinematic coefficients because it provides a convenient transition to the analysis of spatial mechanisms and robots. The graphical and complex vector approaches, which are well adapted to the study of planar mechanisms, are carefully presented as well. The second part is a survey of cams, gearing and linkages, and robot kinematics. The third part presents the force analysis, vibration and balancing of a range of machine systems including engines, flywheels, governors and gyroscopes. My primary concern with this book is that machine theory of the past necessarily focused on the velocity, acceleration and forces in a device at one particular configuration, while it is the value of these parameters throughout the movement that is of interest. Prof. Uicker’s Integrated Mechanisms Program (IMP), which dates back to 1964, was among the first software systems for machine simulation, and Prof. Pennock is a leading researcher in robot and spatial linkage analysis. I hope that their future editions move in the direction of showing students how to analyze and simulate the movement of machine systems using the computers that are available to most all engineers. In any case, this book provides an excellent presentation of machine theory with a depth and breadth that can find use in courses ranging from an undergraduate survey of machine theory to an advanced undergraduate or even graduate level course on machine kinematics and dynamics. Practicing engineers will find this book to be a valuable reference on the principles of machine theory.

Classifying technological knowledge for presentation to mechanical engineering designers

In this paper, we explore various options to classify technological knowledge for mechanical engineering designers. Classification is needed when technological knowledge is presented to designers in an automated knowledge management system (for example, a database that can be accessed by designers through the Internet). In particular, we draw from philosophy of technology, history of technology, and design methodology, to see what classifications can be made. It is not known whether such theoretical classifications are recognised by designers. In the empirical part of our study, we have submitted a number of optional classifications to active mechanical engineering designers to see what classification they would prefer as the basis for an automated knowledge-based system on the Internet. The outcome was that they recognised a classification that had been developed in the context of philosophical and historical studies, and even preferred that compared to more traditional disciplinary classifications.

A contribution to technological data estimation for concurrent engineering using geometrical control of net shape forming parts

Within the framework of integrated design and manufacturing in mechanical engineering, which is now a well-known field, the design of the parts, the choice of process parameters and even the design of the production system must be carried out at the same time. However, in order to achieve full knowledge integration taking into account the actors' knowledge (the intervening people in the process of design and manufacture of a product are named ‘actors’) and their various points of view, it is necessary to formalize and structure this knowledge together with the technical and economical constraints (manufacturing, quality, logistics, cost, etc.). This means that the models and data must be homogeneous, coherent and not user adapted until their actual time of use. In order to give an illustration of this wide-ranging problem a case of application will be presented in the field of the forming process based on two industrial applications that have been carried out. A contribution is proposed for an approach that makes it possible to gather the technological data and information necessary for integrated design and manufacturing in order to obtain net shape forming of workpieces for the automotive industry. Two approaches are presented, on the basis of dimensional control of the workpiece: the first deals with the description of the forming process, and the second covers the definition of product functionality.

An evolutionary shape optimization procedure for contact problems in mechanical designs

The finite element method (FEM) has been extensively applied to explore contact stress distributions in multi-body mechanical systems. Uneven contact stresses are often one of the main concerns of mechanical design engineers. By adopting the evolutionary structural optimization (ESO) concepts, this paper presents a non-gradient procedure for gradual shape redesign of prescribed contact interfaces. In this method, interfacial gaps are considered as design variables and contact stress deviations over design interfaces are set as the objective function. To deal with multiple contact region problems, two different design objectives, namely an individual criteria and a unified criteria, are formulated respectively. Several practical examples show that this method is effective for design problems consisting of single- or multiple-contact regions in mechanical systems, in which a uniform contact stress pattern is the desired optimality criterion.

On the opening mechanism of the aortic valve: some observations from simulations

Viewed from the standpoint of mechanical engineering design, the aortic valve is impressive. However, our understanding of its mechanics is limited by our inability to study its in vivo function closely and in detail. Computer simulation methods offer an alternative approach and a first step towards the construction of a more complete cardiac model is described. The model includes the aortic valve, its leaflets and their supporting root, and the sinuses modelled as nonlinear materials. An explicit finite element code has been used to examine the time-varying displacements of the structure that was subject to pressure distributions, which included left ventricular, aortic and thoracic pressures. It was shown that the leaflets of the valve open by a combination of root expansion in a radial direction and leaflet movement in the direction of blood flow. This was compared to a model in which the aortic root was stiffened significantly, and it was found that this modified valve opened by leaflet folding to give a much smaller orifice. These findings, concerning the importance of root expansion, are in agreement with earlier experimental observations.

Toward the ideal mechanical engineering design support system

This paper details the progress toward the development of the ideal mechanical engineering design support system. It attempts to look at the gap between the needs of a mechanical engineer and what is currently available on CAD systems. Since the term CAD emphasizes that the computer is an aid to the human designer, this paper is designer-centric. It is based heavily on the activities performed by designers and the types of information developed by them. Seventeen goals for the ideal mechanical design support system are listed. These are directed at the types of information developed during the design process and the activities used to develop them. For each of the seventeen, background information, the current state-of-the-art, and opportunities for future development are itemized.

A knowledge-based system for materials selection in mechanical engineering design

This paper studies various work on the development of computerized material selection system. The importance of knowledge-based system (KBS) in the context of concurrent engineering is explained. The study of KBS in material selection in an engineering design process is described. The development in materials databases, which sometimes serve as material selection packages, is also discussed. The use of KBS in material selection and the application in the domain of polymeric-based composite are chosen as typical examples.

Machine Design: A CAD Approach

Machine Design: A CAD Approach

3201 新しい設計教育のひとつの試み : 東工大機械学科「独創機械設計」の紹介(OS06-1/設計教育(1))(OS06/設計教育)

This paper introduces "Mechanical Engineering Design Project" offered to the junior class students of the department of mechanical engineering and science, Tokyo Institute of Technology, since 1993. This is a very challenging subject to seek and establish a new style of education on design engineering. In every year, over 80% junior students of the department take the subject. At first, every student proposes a new machine based on his/her own unique idea. Five proposals are accepted. Then, all students join to one of the five design teams. Each team makes all its members' efforts to design and produce a unique machine. Design drawing and cost accounting are required. One of the most important aims of this subject is to let students experience the enjoyment and the difficulty of designing machines.

Aesthetic factors in geometric modelling

AbstractCAD systems have traditionally catered for architectural and mechanical engineering designs which are somewhat constrained in scope. Problems concerning other types of design such as art design, industrial design or sculpting, where creativity and aesthetic factors play an important role, are not adequately addressed. These types of design require much more flexibility in both geometric modelling capability and user-machine interaction. This paper first gives a brief overview of recent work which deals with creative activities, and analyses important issues that need to be addressed in object representations for 3D creative activities. We then discuss a scheme to categorise and represent aesthetic factors in geometric modelling.

Semi-controlled experiment plans for improved mechanical engineering designs

The use of planned experiments to improve designs is considered for situations where standard plans, such as orthogonal arrays or response surface plans, are impractical. An approach is described that is of special interest to the design of mechanical products where it is expensive to make prototype components to specified dimensions, and only a given small sample of components of diffiering dimensions is available. The plan for the experiment must then make the best use of the available components by determining an assembly that will most efficiently explore the expected design parameter region where the design parameters may be derived from the component dimensions. In contrast to conventional methods, the resulting experiment is semi-controlled, rather than fully controlled, as the component dimensions cannot be chosen but the assembly can. An algorithm for finding such plans is described and an example of its implementation in improving the design of an hydraulic pump is presented. The method extends to studies involving some components whose dimensions cannot be designated and hence are obtained from a small sample, and other components that are easily and cheaply constructed to prescribed dimensions. This results in a combination of semi-controlled and fully controlled factors. Efficient plans for such experiments are described and results from their application in practice are discussed.

3314 機械工学技術者に要求される属性-設計か数学物理か

3314 機械工学技術者に要求される属性-設計か数学物理か

Set-models of information-gap uncertainty: axioms and an inference scheme

The sparsity and complexity of information in many technological situations has led to the development of new methods for quantifying uncertain evidence, and new schemes of inference from uncertain data. This paper deals with set-models of information-gap uncertainty which employ geometrical rather than measure-theoretic tools, and which are radically different from both probability and fuzzy-logic possibility models. The first goal of this paper is the construction of an axiomatic basis for info-gap models of uncertainty. The result is completely different from Kolmogorov's axiomatization of probability. Once we establish an axiomatically distinct framework for uncertainty, we arrive at a new possibility for inference and decision from uncertain evidence. The development of an inference scheme from info-gap models of uncertainty is the second goal of this paper. This inference scheme is illustrated with two examples: a logical riddle and a mechanical engineering design decision.

Object oriented design of an interactive mechanism simulation system – Clodion

Mechanical system simulation software is of fundamental importance to computer aided design in mechanical engineering. Such software systems considerably reduce turn around time and have applications in various industries like automative, aerospace and general machinery. A number of mechanical simulation systems are commercially available. However, many of these systems are legacy systems, not necessarily with modern graphical user interface techniques, and also not necessarily designed with newer simulation algorithms or robustness considerations. In this paper we describe the design of a interactive mechanical system simulation package – Clodion. The package has been designed using object oriented design, with careful use of software structuring and also user interface design principles. The design of Clodion has a number of innovative features in the form of its class hierarchy specifically designed for mechanical systems, its event propagation design methodology and its visualization and other utilities. We also present some results which show the user interaction scheme as well.

Fast optimization of mechanical designs using computer aided design/computer aided engineering emulation: A case study

The use of emulator methods in mechanical engineering design is more limited than in electrical and electronic engineering. The concept is to replace a computer aided engineering simulator with a fast statistical emulator built using a designed computer experiment, which can then be used to facilitate optimization and robust engineering design. This case study draws out lessons for application in mechanical design.