Advances in Engineering Software (1978)最新文献

The paper presents a general purpose computer program capable of analysing any planar frame made up of members which can be categorised as thin-walled members. The approach is based on Vlasov's theory which accunts for coupling between torsion and bending actions. The topic is gaining importance due to the improved techniques of producing cold-formed steel sections which have much higher strength than normal steels. The program is in the form of single-array storage which makes its application easy even by a practicing engineer who cannot go into the details of Vlasov's theory. The program is illustrated by means of an example with complete information about input and output for the particular problem.

The object of the paper is to propose a simple method of mesh generation for objects with complicated boundary configurations and present a program which can generate the element data required for Finite Element Analysis based on these methods. The area to be meshed is considered as a combination of different sub-areas which are further sub-divided into the required number of triangular elements. The main part of the program developed in FORTRAN is included in this paper.

A new data structure, which combines a hierarchical organization with a hypergraph-based representation, is presented. This structure, called a structured hypergraph, is a hierarchy of hypergraphs and combines the two concepts of modular decomposition and of description of an entity at different levels of abstraction. Two basic transformations, called refinement and abstraction, are described. These latter are the basic tools for defining and modifying a structured hypergraph. Applications of this structure as a hardware system model, as a description of the symbol table of modular language, as a hierarchical representation of solid objects, and as a model of computer networks are discussed.

This paper presents a Turbo-Basic program that implements an algorithm for the optimum approximation of real rational functions via linear-programming. The formulation of the linear problem is based on the minimization of a minimax criterion, while its solution is derived through the dual problem. This algorithm is much faster and requires less storage than other approximation techniques. The program is implemented on an IBM-PC AT and tested by several examples. Analytical examples are presented to illustrate how the program is used and the effectiveness of the algorithm.

The last few years have witnessed a large increase in use of computer graphics to simulate the robotic performance. The utilization of graphic simulation and programming has greatly enhanced the design, control, and productivity of robotic applications, especially in manufacturing. When designing and controlling robotic systems, computer graphics can be used to evaluate how the robot will react to and perform within the production environment before significant time, capital, and expense are incurred. Graphic simulation enables the designer not only to select the right robot but also to program it to perform the task in the most efficient way. The purpose of this paper is to review the recent advances in graphic techniques and to evaluate available software packages for simulating the motion of robots. The equipment associated with the software packages is also discussed.

A small library of FORTRAN 77 subroutines which perform certain basic mathematical calculations, and a driver which facilitates interactive access to that library, are presented. By interactive access, we mean that the user has only to answer a series of questions about his or her problem, and a FORTRAN program which calls the desired subroutine will be generated automatically. A key feature of the interactive driver is that it can be easily expanded to allow interactive access to any new subroutines which the user may wish to add to the library.