A general capability of design sensitivity for finite element systems

Abstract

Finite element analysis programs are generally used to analyze s tructural integrity. However, these programs do not normally have a ready made capability of evaluating the e ffects of changing the (henceforth called sensitivity) on the structural behavior. Such a procedure is desirable for effective utilization of materials and resources and for t imely decisions on modifications. A computerized procedure for has been developed using a general purpose finite element program EISIIEAL. The procedure is capable of predicting of (requirements namely stiffness, strength, frequency a nd mode shape) to changes in the parameter.s. The term design sensitivity is used to indicate not only the computation of required derivatives but evaluations of appropriate d irection of moves for different situations and determination of relative i mportance of parameters f or improving performance. The variables can be a combination of the following parameters: sectional, materials, g eometrical and shape-properties pertaining to a generic f inite element model. The procedure is based on efficient derivative c omputations and post processing schemes that reduces the total time and user's involvement. The reliability and effectiveness of the method are examined by applying it t o t he evaluation of two typical problems, a tapered beam and a composite wheel.