Structural Design Sensitivity Analysis via Strain Energy Variations

This paper describes the computer implementation and application of an alternative method of computation of structural design sensitivity coefficients. This method is based on a scheme of analysis of strain energy variations and uses Castigliano's Theorem to compute derivatives of nodal displacements with respect to structural design parameters. The method is particularly useful for structural optimization problems with a large number of design variables and a relatively small number of constraints. It is implemented by pre and post processing results from a structural analysis program; therefore, it can be implemented with no changes to the source code of a structural analysis program. The implementation and application of the method with OPUS [1], Ford's in-house structural optimization system, coupled with the MSC/NASTRAN finite element program [2], are described.