Interactive microcomputer-aided design of shop-welded and field-bolted beam-column connections

A microcomputer-aided design (MicroCAD) system has been developed for interactive design of connections in steel buildings made of standard rolled l-sections, called Steelcon. Design of different connections is based on the American Institute of Steel Construction specification. Connecting elements may be plates, angles, or T-sections. Connectors may be bolts or welds. The MicroCAD system can display/plot any isometric view of the connection plus the orthographic views, i.e. front, side, and top views. The application of the MicroCAD system to the design of simple (type 2) shop-welded and field-bolted beam-column angle and plate connections is discussed. Microcomputer graphics for displaying the isometric and orthographic views including the dimensions and designation are presented. This MicroCAD system can be used effectively for practical design of connections in steel buildings.     

Cladding-network interaction in pretensioned cable roofs, studied by dynamic relaxation

Current methods of analysis and design of pretensioned cable roofs disregard the cladding contribution to the overall stiffness of the structure, and therefore full-scale constructions suffer from excessive pretensioning of the cables. This paper investigates cladding stiffening effects in pretensioned cable roof models, using a dynamic relaxation algorithm. A mathematical model of cladding-network interaction in combined response to static external loads is presented, developed on the assumption of a discrete membrane surface of the cladding attached to the cable network. Detailed results are presented for a partially and fully clad hyperbolic paraboloid model. Comparisons are made between the results from the analysis of the composite structure clad with panels of varying stiffness and the corresponding “bare” network analysis. Results show that the cladding makes a substantial contribution to the stiffness of the composite structure, and suggest that future design of foundations for the cable anchorage should take this into account.     

Interactive garment design

A method for the design of garments at a workstation is proposed. An underlying body form analogous to a trade mannequin is first represented in the computer. Garment panels are considered to be surfaces of complex shape, whose fit with respect to body form may vary over the surface. A method of easy entry of data for representing panels is proposed, whereby fit around panel edges can be defined. The problems of controlling fit in the interior of panels is considered and a scheme is proposed which accomplishes design with economy of effort from the designer.     

Interactive computer-aided formwork design

While disciplines such as structural analysis are reaping the benefits of computer implementation, temporary works design lags well behind. Some of the reasons given by temporary works designers are that their designs are very practical and depend largely on the designer's experience and engineering judgement. By designing a highly interactive user friendly interface, a comprehensive program that runs on IBM compatibles has been developed. The program can be used to design formwork for walls and soffits using traditional timber and/or proprietary formwork components. The program incorporates many features commonly associated with business oriented software interfaces, placing special emphasis on the ease of use and at the same time allowing users to incorporate their own engineering judgement. The user interface features include the use of bar menus, windows and data entry screens. Formwork design may involve the use of material components from different sources, therefore, it is highly data dependent. Consequently, a database management system (DBMS) is used to manage a database of material properties, costs and other attribute data. Formwork members are designed using a rational approach to BS5975: 1982 and the recommendations of the Concrete Society's book Formwork: A Guide to Good Practice. The program produces design details, a schedule of quantities, a cost comparison between purchased and hired proprietary formwork and a cost estimate.     

Interactive control system design

This contribution describes a LabVIEW-based interactive computer-aided control system design tool. Although it does not provide the flexibility of common low-level design tools, it offers a set of comfortable, ready-to-use solutions for plant identification, loop-shaping or LQR/LQG-controller design and controller implementation. The tool integrates into industrial plant control and enables engineers to efficiently do the control system design from plant identification to controller implementation on the same platform. The user interface with convenient system editors and analysis tools facilitates the user to interactively attain the design goals. If desired, a configurable wizard leads the user through the design process.     

Interactive design system application

An interactive design system for the drawing office is described that should provide better control and standardization of drafting procedures, electrical and electronic symbology, repeatable designs and manufacturing processes, thus making it possible to produce higher-quality drawing documents in a shorter time and to increase the capacity of the drawing office.     

Dynamics and flatness-based control of a kinematically undetermined cable suspension manipulator

A kinematically undetermined cable suspension manipulator moves a payload platform in space by several cables with computer-controlled winches, whereby the position of the payload platform is not determined by the lengths of the cables. Trajectory tracking control of the payload platform is achieved by means of the concept of flat systems. A flat system has the property that the state variables and the control inputs can be algebraically expressed in terms of the so-called flat output and a finite number of time derivatives of the flat output. Its application to kinematically undetermined manipulators represents a generalization of computed-torque control. The control forces are algebraically calculated from the desired trajectories of the payload platform and their time derivatives up to the fourth order leading to a feedforward control strategy. Asymptotically stable tracking behavior is achieved by exact linearization of the nonlinear dynamics by means of a so-called quasi-static state feedback. The procedure is described for the trajectory tracking control of the prototype three-cable suspension manipulator CABLEV.     

Interactive graphics for mask design

The advantages of using off-the-shelf components to construct an interactive c.a.d. system are described. The particular application is to the design of masks for integrated circuits.     

Analysis and design of cable structure S

As a class, suspension structures are generally more flexible than framed or trussed structures. A consequency of this flexibility is that factors often need be considered when engineering cable structures which may be neglected when designing more conventional structural systems. Among these factors are: difficulties associated with mathematically defining the suspension structure's initial shape and the member forces corresponding to that state, the nonlinear relationship between changes of loading and displacement, and the susceptibility of some types of cable structures to wind-induced oscillations.

In the paper, cable structures are classified and examples of some types are illustrated together with a discussion of their advantages and disadvantages. The problem of establishing the initial shape of the structure is discussed. Some techniques for computing the displacements of suspension structures resulting from changes in static loading, considering the geometrical nonlinearity, are described. A procedure for determining the displacements of stiffened and unstiffened cable three-dimensional structures is outlined that is suitable for computer solution. Results of numerical studies made utilizing this technique are presented.     

电缆防盗报警器的设计与实现

本文介绍了一种使用单片机和555集成电路制作电缆报警器的方法。通过555集成电路和单片机配合,再加上校验功能,可以比较精确地测量出断缆距机房的距离,为电信运营提供了一种性价比较高的电缆防盗报警装置。     

Interactive design optimization of dynamic systems

This paper describes an interactive environment for dynamic response optimization problems. It is shown that with proper interactive facilities and designer intervention, the optimal design process can be more flexible, efficient and effective in solving practical design problems. The process can be initiated with a rough design model for the problem. As the iterations progress and insight is gained into the problem, the model can be interactively refined, without stopping the process, to obtain the final solution. Two example problems — a system dynamics problem and a control problem — are used to study and show advantages of the designer interaction. It is concluded that interactive optimum design capabilities offer more opportunities to the designer to obtain better designs.     

Interactive optimal design of truss structures

A CAD system based on combining structural optimization methods and graphical interaction is presented. The optimization methods implement the automated decisions and algorithms while the interaction provides the means to implement the designer's decisions. A new interactive optimization procedure for optimal truss design is proposed. The structural topology, geometry and member sizes are treated as design variables. Results show that the system provides a powerful tool to obtain a practical optimum design.     

集中荷载作用下悬索的主共振分析

针对集中荷载作用下两端固定悬索在集中荷载点外激励作用下悬索系统发生的强迫振动,研究了激励频率接近悬索主共振频率时,系统产生的主共振.采用多尺度法,得到了各阶振型的主共振分叉图和主共振分叉点的解析解.通过实例计算,得到了悬索的各阶振型的线性频率与集中荷载以及集中荷载的位置关系,还得到了各阶振型的主共振分叉图和各阶振型的主共振点相平面图.     

Interactive virtual try-on clothing design systems

Clothing computer design systems include three integrated parts: garment pattern design in 2D/3D, virtual try-on and realistic clothing simulation. Some important results have been obtained in pattern design and clothing simulation since the 1980s. However, in the area of virtual try-on, only limited methods have been proposed which are applicable to some defined garment styles or under restrictive sewing assumptions. This paper presents a series of new techniques from virtually sewing up complex garment patterns on human models to visualizing design effects through physical-based real-time simulation. We first employ an hierarchy of ellipsoids to approximate human models in which the bounding ellipsoids are optimized recursively. We also present a new scheme for including contact friction and resolving collisions. Four types of user interactive operation are introduced to manipulate cloth patterns for pre-positioning, virtual sewing and later obtaining cloth simulation. In the cloth simulation, we propose a simplified cloth dynamic model and an integration scheme to realize a high quality real-time cloth simulation. We demonstrate the robustness of our proposed systems by complex garment style virtual try-on and cloth simulation.     

接地电缆防盗器的设计与实现

本文介绍了一种使用单片机和485通信电路制作接地电缆防盗报警器的方法.通过485通信电路和单片机配合,主机端能根据不同的485地址,可以比较精确地判断出具体的报警位置,为电力运营提供了一种性价比较高的电缆防盗报警装置.     

Topology optimization for femto suspension design

The ongoing increase of track density requirements of hard disk drives (HDDs) and decrease of flying height of sliders have brought along formidable challenges to suspension design. Conventional design processes are quite tedious and inefficient. This paper presents a HDD suspension design process by using topology optimization. An efficient structural topology optimization method, based on the second derivatives information, is proposed to generate structures which satisfy multiple design objectives including both compliance and eigenfrequencies. This topology optimization approach is successfully applied in the HDD suspension design. The design begins with a very simple initial draft, and the design objectives are defined to minimize the spring rate and maximize the resonant frequencies of first bending, first torsion and sway modes of a suspension. An optimal design concept can be generated from the topology optimization. Then the design is further tuned by using the shape optimization. Finally, an optimal suspension design for femto sliders with much better dynamic characteristics is presented.     

Interactive design exploration for constrained meshes

In architectural design, surface shapes are commonly subject to geometric constraints imposed by material, fabrication or assembly. Rationalization algorithms can convert a freeform design into a form feasible for production, but often require design modifications that might not comply with the design intent. In addition, they only offer limited support for exploring alternative feasible shapes, due to the high complexity of the optimization algorithm.We address these shortcomings and present a computational framework for interactive shape exploration of discrete geometric structures in the context of freeform architectural design. Our method is formulated as a mesh optimization subject to shape constraints. Our formulation can enforce soft constraints and hard constraints at the same time, and handles equality constraints and inequality constraints in a unified way. We propose a novel numerical solver that splits the optimization into a sequence of simple subproblems that can be solved efficiently and accurately.Based on this algorithm, we develop a system that allows the user to explore designs satisfying geometric constraints. Our system offers full control over the exploration process, by providing direct access to the specification of the design space. At the same time, the complexity of the underlying optimization is hidden from the user, who communicates with the system through intuitive interfaces.     

Interactive graphic editor for circuit design

This document describes the creation and implementation of a CAD system for the Mexican Telephone Administration. The main objective of the system is to help in the design of electric diagrams and printed circuits, thus providing consistency, standardization and reliability. The graphics package consists of two graphic editors and one autorouter developed over a graphics kernel.