Indexed by:会议论文

Date of Publication:1991-01-01

Included Journals:Scopus

Issue:63

Page Number:211-223

Abstract:Sensitivity analysis is one of the cornerstones for the development of computer aided structural shape optimization softwares. The semianalytic sensitivity analysis method proposed in recent years has provided an easy way to integrate the existing general purpose FEM and optimization packages. Nevertheless, the method suffers from an inaccuracy problem if the size of the perturbed bending elements becomes too small. An alternative forward/backward finite difference scheme has been studied to reduce the possible error and implemented in MCADS. This paper further investigates the problem and suggests ways to improve the accuracy of the semi-analytic sensitivity analysis. It is shown in this paper that for annular plate and Euler beam elements the approximate sensitivity calculated with the semi-analytic method can be improved by adding second order terms. For a typical beam example the improvement is estimated by making use of computer algebra software 'MUMATH' to manipulate the approximate sensitivity and its second order correction. Numerical results also show that for Timoshenko beam elements the accuracy of semi-analytic method is much less dependent upon the element size, which is a desirable feature. The second part of the paper introduces MCADS system--a Micro-computer Aided Design System. We have incorporated several of the newest techniques, such as semi-analytic method for design sensitivity analysis, optimization-analysis modeling for shape design, application oriented user interfaces and coupling of automatic optimization and user's intervention into the system. A practical example from industry involving coupling field structural shape optimization is given.