The Dynamic Optimization Design Based On Spectral Response Analysis

The response characteristics of the dynamic system under random excitation are studied in stochastic vibration. There are a lot of stochastic vibration in the fields of machinery, aviation, spaceflight, automobile, shipbuilding and other fields, such as take-off, landing, flight and re-launch of aircraft and so on. To reduce the level of vibration, it will cost a lot of time and money to redesign the structure dimensions. Additional vibration absorber on the structural vibration is one of the effective measures to control the vibration of the structure. The dynamic vibration absorber can be used not only to suppress the deterministic vibration, but also to restrain random vibration. Therefore, it has an extensive engineering application.For the optimization design of mechanical structure with dynamic vibration absorber under random load, the first step is to design absorber’s stiffness structure and mass distribution based on the resonant frequency of the structure that is being isolated, followed by spectrum analysis using modal-reduced model virtual excitation method. Secondly is structural dynamic optimization of both vibration absorber and the main structure. A proper optimization analysis algorithm was used. The optimization target is the power flow through the whole structure under certain rang of frequency, with maximum displacement response of CRMS for the optimization constraints. An analysis of efficiency of isolator was constructed. Last, location optimization was constructed for the absorber to find the best installation location. An application case was demonstrated here with a certain structure. Results show that this vibration absorber has a high efficiency. The reach fills the blank in the field of broadband absorbers and has an important significance in a broader application of vibration absorbers.