EFFICIENT SENSITIVITY ANALYSIS FOR STRUCTURAL OPTIMIZATION

Efficient sensitivity analysis, based on high quality approximations o f displacements, is presented. The improved approximations are achieve d by combining the efficiency of local approximations (series expansio n) and the quality of global approximations (the reduced basis method) . Three approximate sensitivity analysis methods are developed and com pared: the direct method, the adjoint-variable method and the finite-d ifference method. All the approximations are based on the results of a single exact analysis of the initial design, and they can be used wit h a general finite element system. The methods are easy to implement a nd suitable for different types of design variables and structures. It is shown that high quality approximations of derivatives can be achie ved with a relatively small computational effort for very large change s in the design variables.