Approximate reanalysis for modifications of structural layout

The problem of reanalysis of structures subjected to various layout modifications is considered. The study is focused on the following simultaneous changes: the addition of joints and members; the modification of structural geometries; and the alteration of loading conditions. Based on a suitable partition of the modified stiffness matrix and the combined approximation, a reanalysis technique is developed. The implementation of the method is also discussed. Calculation of derivatives is not required. The computational cost is significantly reduced. The numerical examples illustrate the proposed method is quite effective. High quality results can be achieved for great changes in the design.