Optimizing Dynamic Responses of Structures using Isight to Integrate NASTRAN

With the development of science and technology, engineering structures become more and more complex, being required good property, working in random conditions. Ordinary static design method does not satisfy the requirements of structural design .It is more and more important to research the optimal design of structures, being applied random loads. In this paper the mathematic model of structural optimization is established for structures being applied random excitations, with mean square roots of accelerations of points in structure as constraint conditions, structural geometrical scales as design variables and less mass of the whole structure as the goal. Combining the functions of integrating and optimizing of the software ISIGHT with the functions of finite element analysis of software NASTRAN, the random dynamic response optimization can be realized for arbitrary assembled structures. A bracket subjected to random base excitation is shown in the following figure. There are two blocks on the middle plates respectively, to optimize the diameters of pillars and thicknesses of the middle plates to minimize the mean square roots of accelerations of the middle points of the blocks and the weight of the whole bracket. The theoretic computation and experimental validation are done, good results are obtained.