Dynamic Response Optimization Of Structures And Robust Optimal Design In Structural Dynamics

Many structures are not only subjected to static loads, but also subjected to dynamic loads. In most cases, the destructions of structures are mainly caused by dynamic loads (the latter). As to this kind of structures, in order to improve the structures'dynamic properties to get the minimum dynamic responses and to control the vibration, or namely, to ensure that the structures can work on the safe side under dynamic conditions, it is necessary to undertake dynamic design. The present optimization design of dynamic response is mainly concerned with specific projects, failing to have the universality of applying to arbitrary and complicated structures. Therefore, in this paper structural analysis software MSC.NASTRAN and mutisubject optimal design software ISIGHT was integrated to get the two software auto-interlinked and solves the universal problem of current structural dynamic optimal software. Take a bracket is taken as the research subject, the bracket is affected by random base excition. To take the geometry dimension as the design variable, the structural safety as the constraint condition, the optimal objective is to get the least weight of structure and the least mean square roots of vibration accelerations of key points. Using the integration software succeeded in the optimization design of dynamic response of the bracket. In order to proof the correctness of the optimal result, a actual model of the backet was made. From the results of simulation and experiment, it can be seen that the performance of the optimized bracket was improved to a great extent.With the progress of the society and the development of the science and technology, people make higher and higher demand on the systematic performance of the civil engineering in recent years. In the course of people's exploration of improving the systematic performance and the quality of products, Robustness has aroused general interest and more and more researchers have considered it as the criterion of judging the quality of a system. Consequently, robust optimization design emerges as the times demand and it gives full play to solving such kind of problems. In current civil engineering area, the application of robust optimization design in statics has gradually reached maturity. However, most of the applied softwares of robust design only consider the projects in static state and are seldom applied in dynamics. In order to minimize the influence of these uncertain factors, in this paper the robust optimization design of the structure's dynamic response as the further study of the above-mentioned optimization of the dynamic response was studied. To take the Monte carlo method and perturbation finite element method to cope with random factor in structures, the robust optimal mathematic model of structural dynamic responses was developed. The robust optimal designs of a vibration absorber and a door frame under random excitation were done by using MATLAB to make programme. Compared to traditional optimal results, the robust optimal results can make the structures get more steady performances.