STRUCTURAL DESIGN SENSITIVITY ANALYSIS FOR COMPOSITES UNDERGOING ELASTOPLASTIC DEFORMATION

Nonlinear structural design sensitivity analysis for structures underg oing elastoplastic deformation is developed in this paper. The referen ce volume concept is used to unify the shape and nonshape design probl ems. The rate (time-independent) constitutive model is employed to acc ount for the plastic material behavior. In the response analysis, a hi gher order approximation procedure of the integration of the rate cons titutive equations is proposed. The direct differentiation approach (D DA) is adopted to obtain the design sensitivity equation for the respo nse variables. A method of partial differentiation of the rate constit utive equations, which yields a set of linear differential equations i n the partial derivatives of stresses and internal variables with resp ect to the design variable, is included in the DDA procedure. In Part I of this paper, the general theory is described. In Part II, the theo ry is applied to a composite laminated beam problem.