ACCURATE COMPUTATION OF DESIGN SENSITIVITIES FOR STRUCTURES UNDER TRANSIENT DYNAMIC LOADS WITH CONSTRAINTS ON STRESSES

Design sensitivities for structures under transient dynamic loads with constraints on stresses are extremely sensitive to the proper represe ntation of direct and adjoint load vectors in the analysis. It is show n that accuracy within acceptable limits is feasible when a proper rep resentation of load coupled with an optimal mesh is used. In this pape r, we approach this problem by systematically achieving an adaptive me sh and by using a static correction method for adjoint response calcul ation and simple modal superposition for direct response for a specifi ed number of basis modes decided on the basis of some criteria. Design sensitivities calculated for several examples demonstrate how this in tegrated approach works and improves the results of sensitivity calcul ation. (C) 1998 Elsevier Science Ltd.