Parallel-vector design sensitivity analysis in structural dynamics

Abstract

This paper presents a parallel-vector algorithm for sensitivity calculations in linear structural dynamics. Theoretical aspects of an alternative formulation for design sensitivity analysis in linear structural dynamics have recently been presented by the authors. The proposed alternative formulation works efficiently with the reduced system of dynamic equations, since it eliminates the need for expensive and complicated based-vector derivatives, which are required in the conventional reduced system formulation. The relationship between the alternative formulation and the conventional reduced system formulation has been established, and it has been proven analytically that the two approaches are identical when all the mode shapes are included. This paper validates the proposed alternative algorithm through numerical experiments, where only a small number of mode shapes are used. In addition, a modified mode acceleration method is presented, thus not only the displacements but also the velocities and accelerations are shown to be improved. An efficient parallel-vector algorithm for design sensitivity analysis in large-scale structural dynamics is developed, which is then implemented in a parallel FORTRAN (Force) code, PVDSASD. The efficiency of the algorithm is illustrated by analyzing practical structural systems, using the CRAY-2 and CRAY-YMP supercomputers, and making comparison with the sequential version of the algorithm.