基于谱响应分析的动力学优化设计

发布时间：2018-06-04 11:34

本文选题：随机振动 + 减小截至模态的虚拟激励法　；参考：《南京航空航天大学》2014年硕士论文

【摘要】：随机振动主要研究动力学系统在随机激励作用下的响应特性,在机械、航空、航天、汽车、船舶等领域中存在着大量的随机振动,如飞行器的起飞、着陆、飞行过程及再发等等。如果重新设计结构的外形尺寸以降低其振动水平,需要花费大量时间与金钱。在振动结构上安装吸振器是解决结构振动问题的有效措施之一,采用附加吸振器的方法不仅可以抑制确定性的振动,还能抑制随机振动,有着广泛的工程应用。对于受随机载荷的机械结构的动力学优化设计,首先,由被吸振结构的共振频率初步确定吸振器的刚度形式和质量大小,并利用基于减小截至模态的虚拟激励法进行谱响应的计算分析。然后对吸振器和被吸振结构整体进行动力学优化设计,选取合适的优化算法,以吸振器的动能最大为优化目标,以结构若干响应点的随机振动最大位移CRMS值为优化约束条件,分析了动力吸振器的吸振效率。最后,对吸振器的安装位置选择,确定吸振器在结构上的最佳安装位置。算例中以某舱体作为被吸振结构进行了动力学优化设计,结果表明了动力吸振器优化设计的有效性。本文的研究拓展了动力学优化设计在结构力学领域的应用范围。
[Abstract]:Random vibration mainly studies the response characteristics of dynamic system under random excitation. There are a large number of random vibration in mechanical, aviation, aerospace, automobile, ship and other fields, such as the take-off and landing of aircraft. Flight and re-launch, etc. It takes a lot of time and money to redesign the shape of the structure to reduce its vibration level. The installation of vibration absorbers on vibration structures is one of the effective measures to solve the structural vibration problems. The method of adding vibration absorbers can not only suppress the deterministic vibration but also suppress the random vibration, so it has a wide range of engineering applications. For the dynamic optimization design of mechanical structures subjected to random loads, firstly, the stiffness and mass of the vibration absorbers are preliminarily determined by the resonance frequency of the structure. The spectral response is calculated and analyzed by using the virtual excitation method based on reducing the terminal mode. Then the dynamic optimization design of the vibration absorber and the whole structure is carried out, and the appropriate optimization algorithm is selected. The maximum kinetic energy of the absorber is taken as the optimization objective, and the maximum displacement CRMS value of random vibration of some response points of the structure is taken as the optimal constraint condition. The efficiency of dynamic vibration absorber is analyzed. Finally, the optimal installation position of the absorber is determined by selecting the installation position of the absorber. The dynamic optimization design of a cabin as the vibration absorbing structure is carried out, and the results show that the optimal design of the dynamic vibration absorber is effective. The research in this paper extends the application of dynamic optimization design in the field of structural mechanics.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB535.1

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