Showing papers on "Design tool published in 1998"

The Role of Material Objects in the Design Process: A Comparison of Two Design Cultures and How They Contend with Automation:

Abstract: This article compares two cultures of engineering design, one flexible and interactive, the other rigid and hierarchical. It examines the practices of design engineers who use a mixture of paper documents and computer graphics systems and contrasts these with the practices of workers reengineering their own work process and its technological support system, using predesigned software. Based on the idea from actor network theory that objects participate in the shaping of new technologies and the networks that build them, the study reveals that (1) design cultures are intrinsically tied to the way in which their representations are constructed because such representations—sketches, drawings, prototypes—are the heart of design work; (2) such design tools can engage or restrict participation in the design process; (3) politics in the form of management prerogatives can be built into a design tool, influencing the range of creativity allowed and innovation accomplished in a given sociotechnological setting.

Continuum Topology Optimization for Concept Design of Frame Bracing Systems

Abstract: Discrete ground structure topology optimization design methods have to date received considerable attention in structural engineering. An alternative class of structural topology optimization methods, which have not yet received much attention in structural engineering, but which have undergone considerable development in the past decade, are the so-called continuum formulations. In this work, a continuum structural topology optimization formulation is presented and applied to the concept design optimization of structural bracing systems that are needed to stiffen tall structures against sidesway under lateral-wind and seismic-type loading. Although demonstrated here in the context of these specific design examples, continuum structural topology optimization methods are believed to hold potential as a design tool for a wide range of civil engineering type structures. A variety of continuum topology design formulations, including static compliance minimization and eigenvalue optimization, are explored, and solution parameters are varied to show that a number of design possibilities can be realized as solutions.

Communication estimation for hardware/software codesign

Abstract: This paper presents a general high level estimation model of communication throughput for the implementation of a given communication protocol. The model, which is part of a larger model that includes component price, software driver object code size and hardware driver area, is intended to be general enough to be able to capture the characteristics of a wide range of communication protocols and yet to be sufficiently detailed as to allow the designer or design tool to efficiently explore tradeoffs between throughput, bus widths, burst/non-burst transfers and data packing strategies. Thus it provides a basis for decision making with respect to communication protocols/components and communication driver design in the initial design space exploration phase of a co-synthesis process where a large number of possibilities must be examined and where fast estimators are therefore necessary. The fill model allows for additional (money) cost, software code size and hardware area tradeoffs to be examined.

Multidisciplinary design optimization of missile configurations and fin planforms for improved performance

Abstract: The aim of the research described herein was to develop and verify an efficient optimization-based aerodynamic / structural design tool for missile fin and configuration shape optimization. The developed software was used to design several missile fin planforms which were tested in the wind tunnel. Specifically, this paper addresses fin planform optimization for minimizing fin hinge moments, as well as aeroelastic design (flexible fin structures) for hinge moment control. The method is also capable of shape optimization of fin-body combinations with geometric constraints. The inclusion of aerodynamic performance, geometric constraints, and structural constraints within the optimization software facilitates multidisciplinary analysis and design. The results of design studies and wind tunnel tests are described.

Collaborative conceptual schema design: a process model and prototype system

Abstract: Recent years have seen an increased interest in providing support for collaborative activities among groups of users participating in various information systems design tasks such as, requirements determination and process modeling. However, little attention has been paid to the collaborative conceptual database design process. In this article, we develop a model of the collaborative conceptual schema development process and describe the design and implementation of a graphical multiuser conceptual schema design tool that is based on the model. The system we describe allows a group of users to work collaboratively on the creation of database schemas in synchronous (same-time) mode (either in a face-to-face or distributed setting). Extensive modeling support is provided to assist users in creating semantically correct conceptual schemas. The system also provides users with several graphical facilities such as, a large drawing workspace with the ability to scroll or “jump” to any portion of this workspace, zooming capabilities, and the ability to move object(s) to any portion of the workspace. The unique component of the system, however, is its built-in support for collaborative schema design. The system supports a relaxed WYSIWIS environment, i.e., each user can control the graphical layout of the same set of schema objects. The system ensures that changes/additions made by any user are consistent. Any conflicts that may compromise to the integrity of the shared schema are flagged and resolved by the system. The results from a preliminary experiment suggest that the use of our system in a collaborative mode improved information sharing among users, minimized conflicts, and led to a more comprehensive schema definition.

Introduction to NuMAD: A numerical manufacturing and design tool

Abstract: Given the complex geometry of most wind turbine blades, structural modeling using the finite element method is generally performed using a unique model for each particular blade analysis. Development time (often considerable) spent creating a model for one blade may not aid in the development of a model for a different blade. In an effort to reduce model development time and increase the usability of advanced finite element analysis capabilities, a new software tool, NuMAD, is being developed.

Computer graphics and architecture: state of the art and outlook for the future

Abstract: During the three decades since Ivan Sutherland introduced the Sketchpad system [7], there has been an outpouring of computer graphics systems for use in architecture [3, 5]. In response to this development, most of the major architectural firms around the world have embraced the idea that computer literacy is mandatory for success. We would argue, however, that most of these recent developments have failed to tap the potential of the computer as a design tool. Instead, computers have been relegated largely to the status of drafting instruments, so that the "D" in CAD stands for drafting rather than design. It is important that future architectural design systems consider design as a continuous process rather than an eventual outcome.The advent of computer graphics technology has had an impact on the architectural profession. Computer graphics has revolutionized the drafting process, enabling the rapid entry and modification of designs (see Figure 1). In addition, modeling and rendering systems have proven to be invaluable aids in the visualization process, allowing designers to walk through their designs with photorealistic imagery (see Figure 2) [6, 2, 3]. Computer graphics systems have also demonstrated utility for capturing engineering information, greatly simplifying the analysis and construction of proposed designs. However, it is important to consider that all of these tasks occur near the conclusion of a larger design process. In fact, most of the artistic and intellectual challenges of an architectural design have already been resolved by the time the designer sits down in front of a computer. In seeking insight into the design process, it is generally of little use to revisit the various computer archives and backups. Instead, it is best to explore the reams of sketches and crude balsa models that fill the trash cans of any architectural studio.In architecture, as in most other fields, the initial success of computerization has been in areas where it frees humans from tedious and mundane tasks. This includes the redrawing of floor plans after minor modifications, the generation of largely redundant, yet subtly different engineering drawings and the generation of perspective renderings.We believe that there is a largely untapped potential for computer graphics as a tool in the earlier phases of the design process. In this essay, we argue that computer graphics might play a larger role via applications that aid and amplify the creative process.

Modal-Based Enhancement of Integrated Design Optimization Schemes

Abstract: The modal approach to integrated structural optimization of aircraft structures offers huge computational savings with acceptable loss of accuracy. The addition of the modal option to existing full-order discrete-coordinate optimization schemes is shown in this paper to provide a very flexible design tool with improved cost effectiveness in typical aerospace design cases. Extensive changes in the modal-based formulation are introduced to expand the scope of its applicability, particularly in the static disciplines. Fictitious masses are used to account for local effects caused by concentrated loads. High-order modal perturbations are introduced for improved accuracy with large move limits. An optional hybrid approach allows the use of modal aeroelastic trim with subsequent discrete-coordinate stress/strain analysis. The new formulation includes the necessary sensitivity analysis for an adequate application in conjunction with the modeling tools of the discrete approach. Tradeoff studies with a realistic generic fighter aircraft model demonstrate the new capabilities.

Destructive disassembly to support virtual prototyping

Abstract: The design paradigm called virtual prototyping (VP) is important because of the need to manufacture products in a short period of time and in a cost effective manner. By replacing the building of physical prototypes for testing various design issues such as usability, life-cycle analysis, functionality and so on with so called “virtual models” on a computer and analyzing them, virtual prototyping is achieved. One of the design issues that has become increasingly important is the “design-for-disassembly (DFD)” paradigm. A well designed product that is easy to disassemble has the obvious advantages when it needs to be taken apart for service or end-of-life recycling. Therefore a design tool that can tie the DFD issues into a virtual prototyping system is of considerable interest. This paper attempts to address this particular issue in the virtual prototyping area: DFD as applied to VP. This paper presents an overview of a detailed DFD method. An algorithm that can be readily tied into a computer aided desig...

Transforming the Theorem Prover into a Digital Design Tool: From Concept Car to Off-Road Vehicle

Abstract: As digital designs grow evermore complex and design cycles become ever shorter, traditional informal methods of design verification are proving inadequate. Design teams are increasingly turning to formal techniques to address this “verification crunch”. The theorem prover, with its emphasis on establishing correctness, is arguably the dream design verification tool; however, theorem provers are rarely used in digital design. Much like automotive industry “concept cars”, theorem provers provide a compelling vision of the future, but in the real world of industrial design they have proven to be difficult to drive and expensive to maintain. We suggest ways that the theorem prover “concept cars” of today can be adapted to become the “off-road vehicles” necessary to negotiate the rough-and-tumble terrain of digital design in the 21st century.

The END: a network adapter design tool

Abstract: We present the design and implementation of the Emulated Network Device (END), a network adapter design tool that facilitates accurate evaluation of alternative adapter designs. Using device emulation, the END permits designers to couple a representative model of an adapter with a real host and its communication software. Different adapter designs can be evaluated and compared accurately in a realistic setting, i.e., while capturing host-adapter concurrency and interaction overheads, before building a prototype. We present the architectural framework adopted by the END and demonstrate its feasibility via a case study of a commercial network adapter. Several design improvements to alleviate performance bottlenecks are realized and evaluated using the END, highlighting its utility as a network adapter design tool.

System and method for concurrent placement of gates and associated wiring

Abstract: A design tool for integrated circuits includes a placement tool which places logic gates and interconnect components concurrently. Probabilistic interconnect models are used to represent the collection of possible interconnect routings that provide acceptable circuit performance and routing area.

Using Advanced Driving Simulator as Design Tool in Road Tunnel Design

Abstract: To obtain more information for tunnel design problems, a virtual model of some proposed tunnel designs was developed to demonstrate the design in advance and to be used as a platform for future tunnel research projects. By combining this model with an advanced driving simulator, the designers can virtually drive through their drawings before construction work is started. In comparison with traditional animation techniques, an interactive virtual model combined with a driving simulator has proved to be useful in many aspects. It is an excellent tool for testing proposed positions of road signs in the tunnel. It is easier to compare alternative sign positions with the three-dimensional virtual tunnel model than with ordinary drawings. Some visual traps not foreseen in the original sign-position design were corrected after detection in the simulator. Traffic engineers reported that they became involved in the tunnel design process at an earlier stage than before, enabling them to work in the final tunnel env...

Asphalt overlay design methods for rigid pavements considering rutting, reflection cracking, and fatigue cracking

Abstract: The overall objectives of this study were (1) to provide basic performance evaluation of asphalt overlays on rigid pavements and (2) to provide a design tool for supporting a long-range rehabilitation plan for the US 59 corridor in the Lufkin District. A factorial overlay method was applied to several test sections with the objective of preventing recurrent problems such as reflective cracking. Data collection was carried out before, during, and after the construction of the test sections under a carefully designed monitoring program. In addition, weigh-in-motion (WIM) devices were installed at the test sites to collect traffic-related information as well as pavement surface and ambient temperature. The performance at the initial stage of the overlay was evaluated based on the following information: (1) detailed traffic information such as axle weights and lateral displacement; (2) distress conditions on different overlays; and (3) effects of previous pavement conditions and overlay recipes on overall performance of the pavements. Mechanistic models were developed using a finite element method (FEM) in a multipurposed program (ABAQUS). The objective of this FEM modeling effort was to establish a reasonable structural design scheme for the overlays on flexible bases for protecting the pavement from both reflective cracking and rutting development. Finally, design equations were developed by using a fractional factorial design. An analysis of variance (ANOVA) was performed to identify significant factors, and a design equation was developed using regression analysis. To minimize costs, an asphalt overlay design method using linear programming was proposed.

Nonlinear damping in vehicle lateral control: theory and experiment

Abstract: The sensor and actuator limits in real-world control systems imposes unavoidable tradeoffs between performance and the size of the operating region. When linear control design techniques are used, these limits are either neglected or accounted for by lowering the gains of the controller. The former results in severe reduction of the operating region, while the latter yields low performance. These tradeoffs can often be mitigated by using a nonlinear control strategy, in which nonlinear terms are intentionally introduced in order to implement different design objectives in different operating regions. In this paper, nonlinear damping is utilized as a design tool in lateral control of automated vehicles. Design considerations of the vehicle lateral controller include lateral tracking errors, passenger ride quality and reference/sensing system characteristics. It is shown that the intentionally introduced nonlinear damping term in the feedback loop possesses several favorable design features in the lateral control system. Experimental results using a full scale automated vehicle show that passenger comfort can be enhanced for small errors by significantly reducing the original controller gains, while at the same time achieving the same level of maximum lateral tracking errors.

Digital Space: Designing Virtual Environments

Abstract: From the Publisher: Create realistic 3D environments with ease. Harness the latest computer-generated 3D imaging techniques to design exciting virtual environments. Peter Weishar's Digital Space shows you how to solve design problems with today's easy-to-use software. . . apply the traditional methods of scenic designers,painters,and architects to create 3D images. . . and optimize all aspects of your 3D models. packed with nearly 200 illustrations,this expert design tool enables you to: create models,set designs,lighting,textures,interiors and exteriors,perspective and trompe l'oeils; apply such digital techniques as fly-throughs,texture-mapping,ray tracing and radiosity; take advantage of tips and shortcuts for faster execution,reduced file size and simulations; and much more! Take control of the latest technology in 3D design with this comprehensive guide for architects,designers,illustrators,and graphics professionals. Digital Space provides start-to-finish,how-to instructions of 3D design that close the gap between software manuals and traditional architecture and design books. Chapters include: industry overview. . . planning. . . space design. . . modeling. . . lighting. . . textures. . . interior space. . . exterior space. . . rendering. . . tips and techniques. . . glossary of terms. The non-technical language and abundant illustrations make Digital Space: Designing Virtual Environments one of the most accessible guides to 3D design on the market. From basic concepts to sophisticated applications,it covers: the design process; optimal working techniques; 3D modeling; methods of streamlining complex tasks; real world case studies;extensive interviews with famous 3D artists.

Component-Based Information Systems Development Tool Supporting the SYNTHESIS Design Method

Abstract: An approach intended to fill in the gap between the existing Object Analysis and Design (OAD) methods applying mostly top-down technique and the demand of the middleware architectures (OMG CORBA) for the information system development based on composition of pre-existing interoperating components is discussed. An overview of the SYNTHESIS method for component-based interoperable information systems design is presented. The heuristic procedure for the most common reduct construction for a pair of ontologically relevant type specifications is outlined. The refinement property of the common reduct leads to a justifiable identification of reusable component fragments. The process of design is based on such identification driven by ontologically relevant pairs of types. The common reducts discovered are composed further to construct specifications serving as concretizations of the required types. The structure and functions of the design tool supporting the SYNTHESIS method and a process of design under the tool are considered.

The ranking of efficiency of structural layouts using form factors. Part 1: design for stiffness

Abstract: This paper presents a method for ranking the mass efficiency of simple structural layouts for stiffness design using form factors. Form factors are derived for three different frameworks and seven different beams for an example load case of a simply supported and centrally loaded structure. The form factors show how structural efficiency is affected by four different design aspects: (a) severity of height constraint, (b) uniformity of stress, (c) utilization of height and (d) principle of load transfer. Form factors can be used as a preliminary design tool to help select and design structural concepts.

Renomo—a Design Tool for Evaluations Designing Evaluations Responsive to Stakeholders' Interests by Working with Nominal Groups Using the Moderation Method

Abstract: Evaluators designing evaluation studies that are responsive to the interests of the different stakeholding audiences have to cope with conflicts and constraints from the very beginning of their work. This article describes a tool for a stakeholder-orientated evaluation approach which combines Nominal Group Techniques and the Moderation Method. The tool is presented in a detailed scenario for an evaluation design context. The paper concludes with an assessment of the utility and areas of application of the RENOMO instrument.

Chrono : A conceptual design framework for temporal entities

Abstract: Database applications are frequently faced with the necessity of representing time varying information and, particularly in the management of information systems, a few kinds of behavior in time can characterize a wide class of applications. A great amount of work in the area of temporal databases aiming at the definition of standard representation and manipulation of time, mainly in relational database environment, has been presented in the last years. Nevertheless, conceptual design of databases with temporal aspects has not yet received sufficient attention. The purpose of this paper is twofold: to propose a simple temporal treatment of information at the initial conceptual phase of database design; to show how the chosen temporal treatment can he exploited in time integrity enforcement by using standard DBMS tools, such as referential integrity and triggers. Furthermore, we present a design tool implementing our data model and constraint generation technique, obtained by extending a commercial design tool.

Ontological Commitments in Knowledge-Based Design Software: A Progress Report

Abstract: The increased sensitivity of engineered products to external forces requires new computer-based design tools that can express the richness and complexity of product knowledge. This paper is a progress report of the author’s research towards the development of such a knowledge-based design tool, called the Design Knowledge Specification Language (DKSL). A key goal is to ensure the maximum possible logical rigor. In order to do this, ontological commitments are constructed to map logical structures to the domain of design knowledge. The first part of the paper discusses a number of ontological commitments the author has discovered for design. The second part of the paper presents the current, incomplete implementation of DKSL. An example of the structural and steady-state thermal analysis of a wall is used to present DKSL’s capabilities. Although much work remains to be done, it appears that DKSL may be able to accurately and rigorously describe any design knowledge.

A Framework for Preliminary Design of Aircraft Structures Based on Process Information

Abstract: This report discusses the general framework and development of a computational tool for preliminary design of aircraft structures based on process information. The described methodology is suitable for multidisciplinary design optimization (MDO) activities associated with integrated product and process development (IPPD). The framework consists of three parts: (1) product and process definitions; (2) engineering synthesis, and (3) optimization. The product and process definitions are part of input information provided by the design team. The backbone of the system is its ability to analyze a given structural design for performance as well as manufacturability and cost assessment. The system uses a database on material systems and manufacturing processes. Based on the identified set of design variables and an objective function, the system is capable of performing optimization subject to manufacturability, cost, and performance constraints. The accuracy of the manufacturability measures and cost models discussed here depend largely on the available data on specific methods of manufacture and assembly and associated labor requirements. As such, our focus in this research has been on the methodology itself and not so much on its accurate implementation in an industrial setting. A three-tier approach is presented for an IPPD-MDO based design of aircraft structures. The variable-complexity cost estimation methodology and an approach for integrating manufacturing cost assessment into design process are also discussed. This report is presented in two parts. In the first part, the design methodology is presented, and the computational design tool is described. In the second part, a prototype model of the preliminary design Tool for Aircraft Structures based on Process Information (TASPI) is described. Part two also contains an example problem that applies the methodology described here for evaluation of six different design concepts for a wing spar.

Hydrofoil design and optimization for fast ships

Abstract: The paper presents a multi-discipli nary design/optimization method for the conceptual design of a hydrofoil based fast ship. The method is used to determine the maximum achievable lift-to-drag ratio (L/D) of an isolated foil-strut arrangement (hopefully greater than 50) at high transit speeds (greater than 75 knots) while lifting masses of 5,000 and 10,000 tons. First, the tools necessary for the study are presented. They comprise a panel method to compute threedimensional flows around arbitrary configurations with a model for the free surface, a foil cross-section optimization tool, a strut crosssection design tool, and a structural analysis tool. The computational tools are then integrated into a multi-disciplinary design/optimization approach, which is applied to the design of single foil and biplane configurations. Results show that the goal of L/D = 50 is achievable for 75 knots (assuming that techniques can be developed for reducing the skin friction drag to a quarter of its nominal value) and, that for 90 knots, L/D ratios around 45 can be reached. The corresponding break horsepower requirements for 10,000 tons are around 130 khp and less than 200 khp, respectively.

Aerodynamic design sensitivities by automatic differentiation

Abstract: The theme is the automatic-differentiation methodology for calculating sensitivity derivatives from advanced CFD codes. Previously documented success and recent advances are discussed; the computational advantages and disadvantages of this methodology are reviewed in comparison with other well-known competing methods. The feasibility of the technology as a practical design tool is assessed in the context of its application to practical aerodynamic design problems — in particular, aircraft design.

Simulation models for hybrid buses

Abstract: Design and production of hybrid buses in Italy are assisted by a range of engineering tools that enable simulation and optimization of the hybrid bus performance. A review of these tools is given, involving the study and development of typical driving patterns and behaviour, the mathematical models of the components in the hybrid powertrain and, finally, the application of the computer codes.Initially simulation is a design tool. Moreover, it is found that simulation is useful for verifying the suitability of hybrid buses for the required service. By means of more or less complex algorithms, customers can be advised to adapt bus lines and to adjust powertrain parameters.

Boundary Element Method Analysis OfThe Electric Field Of Electrostatic Separators

Abstract: The efficiency of the various electrostatic technologies of air purification, powder deposition or paint spraying is intimately related to the optimisation of the employed electrode configurations. The analysis of the electric field has already proven its utility in this respect. The aim of this paper is to demonstrate that the boundary element method (BEM) is appropriate for the study of rolland plate-type electrostatic separators, two groups of devices which are characterised by intricate electrode configurations. A BEM program, developed at Worcester Polytechnic Institute (USA) and provided with interactive data input, error checking facilities and procedures for plotting equipotential and/or flux lines, was successfully employed for the evaluation of field uniformity and breakdown conditions in various electrode arrangements. The computed results showed how the electric field distribution can be modified by changing the electrode shape, size and position. The program was used as an effective design tool for developing several models of industrial electrostatic separators at the Technical University of Cluj-Napoca (Romania). Nevertheless, the role of computer modelling should not be overestimated: numerical analysis of the field provides useful data for an appropriate design, but cannot serve as a complete substitute for experimental testing of new technical ideas. Transactions on Modelling and Simulation vol 19, © 1998 WIT Press, www.witpress.com, ISSN 1743-355X