EFFICIENT SENSITIVITY ANALYSIS FOR STRUCTURAL OPTIMIZATION

Efficient sensitivity analysis, based on high quality approximations of displacements, is presented. The improved approximations are achieved by combining the efficiency of local approximations (series expansion) and the quality of global approximations (the reduced basis method). Three approximate sensitivity analysis methods are developed and compared: the direct method, the adjoint-variable method and the finite-difference method. All the approximations are based on the results of a single exact analysis of the initial design, and they can be used with a general finite element system. The methods are easy to implement and suitable for different types of design variables and structures. It is shown that high quality approximations of derivatives can be achieved with a relatively small computational effort for very large changes in the design variables.