CAE Systems Research Articles

A CAD-CAE Integrated Injection Molding Design System

. In the injection molding design process, interaction between design and analysis is very intensive. This is to ensure that the plastic part being designed is manufacturable by the injection molding process. However, such interaction is not supported by current computer-aided systems (CAD and CAE), because design and analysis are realized as isolated modules. Although most of CAE systems provide built-in modeling tools, these are only meant for developing an analysis model with very limited CAD functionality. On the other hand, some CAD systems have allowed certain CAE systems to run under their environments, but inherently they use different data models, thus communication between them is poor. This paper presents an innovative, CAD-CAE integrated, injection molding design system. This system uses an integrated data model for both design and analysis. The system is built on top of existing CAD and CAE systems, which not only greatly saves development effort, but also makes full use of the strong functionality of commercial computer aided systems. The system architecture consists of four layers: a CAD and CAE platform layer; a CAD-CAE feature layer; a model layer; and a GUI layer. Two design cases were studied to illustrate the iterative design-analysis process and use of the developed system.

Development of Automated Analysis System for Model Plane Engine Using Fuzzy Knowledge Processing

This paper describes a new automated analysis system for model plane engine. An automatic finite element (FE) mesh generation technique, which is based on the fuzzy knowledge processing and computational geometry technique, is incorporated into the system, together with one of commercial FE analysis codes, ANSYS, and one of commercial solid modelers, Designbase, The system allows a geometry model of concern to be automatically converted to different FE models, depending on physical phenomena of plane engine to be analyzed, i.e. deformation analysis, thermal analysis and so on. The FE models are then automatically analyzed by the FE analysis code. Among a whole process of analysis, the definition of a geometry model, the designation of local node patterns, the assignment of material properties and boundary conditions onto the geometry model are only the interactive processes to be done by a user. The interactive operations can be processed in a few minutes. The other processes which are time consuming and labour-intensive in conventional CAE systems are fully automatically performed in a personal computer environment. The proposed analysis system is successfully applied to evaluate a model plane entwine.

Feature-based CAD-CAE integration model for injection-moulded product design

One prominent characteristic of product design for injection-moulded parts is that design and analysis (e.g. flow simulation) go hand in hand to ensure that the design is manufacturable by the injection-moulding process. Despite the wide use of CAD and CAE systems, the two processes are still not integrated. There is no generic, unified model that allows both design and analysis information to be specified. In this paper, a feature-based CAD-CAE integration model is proposed to tackle the problem. The model comprises a hierarchy of CAD-CAE features such as part, wall, hole, rib, boss and treatment. The features are defined by their attributes and behaviours. With this model, information relating to both design and analysis can be specified and modified. The specified information from the design process is used to activate relevant CAE analysis routines, thus supporting integration from the CAD to the CAE process. If any of the specified design constraints is not satisfied from the CAE results, the initial model can be modified and the CAE analysis executed again. Hence, the model also supports integration from the CAE to the CAD process. A design case illustrates the bidirectional integration process.

Reference models for the computer aided support of simultaneous engineering

The results of research carried out in the world of reference models to assist in the selection of the model(s) that best set the context and basis for the definition of a reference model for the computer aided support of simultaneous engineering are presented. The reference models employed are the Open System Architecture for Computer Integrated Manufacturing (CIMOSA) and the Reference Model for Open Distributed Processing (RM-ODP). The CIMOSA model is appropriate because it enables us to set the context and requirements for CAE systems within an integrated enterprise. The RM-ODP allows the definition of the structure and characteristic of the CAE systems in terms of five different views (enterprise, information, computational, engineering and technology). The result of the research is a CAE framework targeted to assist in the system specification, development and integration of future computer-based systems that support Simultaneous Engineering. A case study is presented to demonstrate the use of the CAE framework.

A QFD based methodology for evaluating a company’s PDM requirements for collaborative product development

CAD, CAM, CAE and CIM systems with their ability to quickly generate and change product data have strained the conventional systems used to manage data. As a result, the time spent by an engineer in looking for the right information far exceeds the time spent on the actual design work. A product data management system is a tool that helps engineers and others manage both data and the product development process, and hence support a concurrent engineering framework in a company. Although PDM systems provide numerous benefits to a company, there are problems associated with firstly identifying an appropriate system for a company and then in its implementation. For a successful implementation of a PDM system it is important for a company to first evaluate its requirements. This paper proposes a QFD (quality function deployment) based methodology for evaluating a company’s current status vis‐à‐vis PDM implementation.

Stamping Blank Optimal Layout and Coil Slitting Widths for Single and Multiple Blanks

In stamping, operating costs are dominated by raw material costs, which can typically reach 75 percent of total costs in a stamping facility. In this paper, material utilization efficiency is modeled by considering two primary sources of scrap: material cut away from the exterior of each blank on the strip and off-cuts of unusable narrow strips generated when wide master coils are slit into strips for subsequent stamping. Based on these, layout optimization techniques for minimizing raw material usage are described that predict the optimal blank orientation on the strip and the optimum slitting width for the strip. In addition, methods are given for determining optimal common strip widths for multiple parts, both for dependent and independent demand. These algorithms are ideally suited for incorporation into die design CAE systems.

Investigation of sheet metal forming by numerical simulation and experiment

Two large sheet-forming simulation CAE systems — Autoform and Ls-dyna3D — being representatives of implicit and explicit solutions, respectively, are employed in the comparison of simulation results for a side-frame constituting the outer panel of a Santana 2000; validating experiments are also presented in this paper. Through the simulation calculation, the engineering strain and the thickness change of the blank during forming are compared and the comparison between the strain state and the FLD is given. The possible areas of wrinkling and failure in the course of pressing are determined. According to the comparison, the difference produced by two systems in dealing with problems is discussed, the cause of existing difference is analyzed and methods of reducing the difference are presented. Finally, the advantages and disadvantages of the two systems are considered.

CAE Systems for Gear Design and Manufacturing as Concurrent Engineering Tool.

It is very important to select proper material and heat treatment process for gear manufacturing. If the manufacturing conditions can be optimized in the design stage before catual trials, the total cost and lead-time can be reduced drastically. In this study, CAE systems have been developed for gear design and manufacturing by considering concurrent engineering approach. The systems are based on mathematical models for thermo-elasto-plastic behaviors during heat treatment. The objective is to predict microstructure and hardness distribution, as well as distortion and residual stresses quantitatively in design stage. A parameter such as a ratio of the fatigue strength and stresses occurred during engaging is proposed to evaluate gear strength. The fatigue strength can be estimated from calculated hardness and residual stresses considering non-metallic inclusions. In addition, a specific pre-and post-processor have been developed for user friendly operation. The calculated results of test pieces and practical gears are in good agreement with experimental ones. Finally, several examples have been reported to show that these CAE systems are useful for practical work.

CAE‐Systeme für die Prozeßleittechnik

CAE systems for the workings of chemical engineering plant have reached a high level of functionality and system architecture. This also applies to process control systems. What is now needed is the integration of the different systems in order to avoid unnecessary duplication of effort, data inconsistency, and time wastage. Fortunately, there are various approaches permitting such integration. Starting from the underlying system architecture, this paper therefore presents a variety of integration concepts. Some of these are propriety solutions because they are based on various manufacturers' products. However, STEP and CORBA also involve standards-based technologies. The time required for their realisation is better estimated in years.

A general methodology for developing intelligent CAE systems — a model-based reasoning approach

A general methodology for developing intelligent CAE systems is presented, which is based on a so-called Model Based Reasoning Approach (MBRA) in knowledge engineering. Generic features of CAE systems are described, and a generic model for the architecture of CAE systems with these generic features is then presented. A model-based reasoning approach is modified for implementing the generic model. A case for developing a computer system for the mechanism design based on a specific finite element theory is used to explain the methodology.

Driving concurrency in a distributed concurrent engineering project team: a specification for an Engineering Moderator

SUMMARY Industry requires CAE systems of the future to be highly flexible and to provide support on multiple levels: assisting the activities both of individual engineers and of complete product design teams. The CAE system must provide accurate, consistent information to all users. It should also actively promote exchange of information and knowledge between team members. In outline an architecture for CAE systems of the future is proposed, and the purpose and structure of the various elements of this architecture are discussed. In particular a specialist, supervisory, co-ordinator application, called the Engineering Moderator is introduced in detail, and its performance requirements specified. This application addresses some fundamental requirements for provision of support for team working in a concurrent engineering environment, by encouraging and facilitating communication between team members.

実装設計と検査技術 ＬＳＩパッケージＣＡＥシステム

実装設計と検査技術 ＬＳＩパッケージＣＡＥシステム

Development of Integrated CAE system for Design Ship Structure in CIM

Recently, an economic environment of industry changes for the worse in Japan. Therefore, a new strategy is necessary to get more competitive technology in design stage of ship. A new concept which is called ADDA (ADvanced Design by Analysis) is now introduced.In order to realize “Advanced Design by Analysis”, Computer Aided Engineering systems should be discussed from the standpoint of integrated system. In this paper, the following systems are integrated by using the concept of product definition system.1) System for calculation trim, stability, and so on.2) System for calculation of ship motions and wave pressure.3) System for calculation of strength for ship structure.4) System of short-term and long-term predictions for local stresses.In order to integrate those systems, some kinds of revision in product definition system which were implemented in SODAS were carried. And furthermore, new input and output generator for the respective CAE systems are made.The integrated system makes it possible to carry ADDA in a relatively short time. The actual processing time for a special ship was 20 hours. Therefore, designers who have to design a new ship are able to carry ADDA more than once by using this system.

Design methodology for a braided cylinder

In this study, the design methodology for a braided cylinder was presented. The concept of an analytical model which involved both micro model and macro model was proposed. The analytical method was applied to estimate the rigidity and elastic limit of a braided cylinder subjected to bending and torsional load independently and as combined load. Using the analysis method, the design of a braided cylinder would be carried out in consideration of the factors that decide the mechanical properties of braided cylinder. This method has the possibility to be useful for structural design of braided composites and can be included as a unit in CAE systems for braided composites.

Methods and Tools for Modelling Manufacturing Information to Support Simultaneous Engineering

A novel approach to the development of a manufacturing information model, which forms part of a CAE system for simultaneous engineering is presented. The combined use of reference models (CIM-OSA and RM-ODP), an object oriented methodology (Booch), a function modelling method (IDEFO), an information modelling language (EXPRESS). and computer tools is reported. The importance of using reference models for the definition, design implementation of CAE systems is outlined. Modelling methodologies that effectively map the specification of the reference models are described and theeir usage is explained.

SHADE: Technology for Knowledge-based Collaborative Engineering

Effective information sharing and decision coordination are vital to collaborative product development and integrated manufacturing. However, typical special-purpose CAE systems tend to isolate information at tool boundaries, and typical integrated CAE systems tend to limit flexibility and process innovation. The SHADE (SHAred Dependency Engineering) project strikes a balance between these undesirable extremes by supporting reconfigurable exchange of engineering knowledge among special-purpose CAE systems. SHADE's approach has three main components: a shared knowledge representation (language and domain-specific vocabulary), protocols supporting information exchange for change notification and subscription, and facilitation services for content-directed routing and intelligent matching of information consumers and producers.

The ANDECS Design Environment for Control Engineering

ANDECS belongs to the new generation of open CAE systems for computational experimenting in controlled dynamic systems simulation, analysis, and multi-objective optimization. Strict databased function modularization with neutral object-oriented data- and model interfaces allows a flexible configuration of application programs. This modularity also guarantees side-effect free functional extensions by an application programmer. Module operation can be switched any time from interactive line commands to an X-Window graphical user interface. Via macro scripts stored on database, module sequences can be operated in batch mode with automatic parameter incrementation. Function modules are available for basic mathematical methods, control methods, simulation, parameter- and trajectory optimization, and interactive visualization for result- and algorithm animation.

A product modeling system for top-down design of machine assembly with kinematic motion

The objective of this research is to develop a product modeling system to support mechanism design from the beginning of the design. The system must cope with two aspects of the design process which are top-down design and preliminary design. The current capabilities of existing CAD and CAE systems are not sufficient to support these two aspects. In this research a modeling method with an abstract model and an incompletely defined model is proposed. The mechanism is presented by constraints and depault values because constraints are suitable for representing the abstract model for a mechanism and default values are useful to supplement an incompletely defined model. We also introduce module-based modeling with mechanism modules corresponding directly to the functionalities of the mechanism and show that it is suitable for top-down design. Incomplete constraints are solved with default values so that the shape and location of the incompletely defined model can be modified and the motion of the model can be simulated. Finally, we illustrate the mechanism modeling system with some examples.

Integrated physics-oriented statistical modeling, simulation, and optimization (MESFETs)

Physics-based modeling of MESFETs is addressed from the point of view of efficient simulation, accurate behavior prediction and robust parameter extraction. A novel integration of a large-signal physics-based model into the harmonic balance equations for simulation of nonlinear circuits, involving an efficient Newton update, is presented and exploited in a gradient-based FAST (feasible adjoint sensitivity technique) circuit optimization technique. For yield-driven MMIC design a relevant physics-based statistical modeling methodology is presented. Quadratic approximation of responses and gradients suitable for yield optimization is discussed. The authors verify their theoretical contributions and exemplify their computational results using built-in and user-programmable modeling capabilities of the CAE systems OSA90/hope and HarPE. Results of device modeling using a field-theoretic nonlinear device simulator are reported.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Special feature. The CAPM/CAE interface within CIM system approaches in medium-sized companies

This article concerns approaches to CIM system development in medium-sized UK manufacturing companies. Alternative views of CIM are presented, illustrated by case studies of medium-sized companies engaged in linking their CAE and CAPM systems. The conclusion reached is that the most realistic path towards CIM for this size of company is one determined by a business-oriented justification for investing in each element. The conceptual frameworks developed for larger companies, e.g. CIM-OSA, pay insufficient attention to existing AMT investments to be able to produce CIM programmes that medium-sized companies can afford.