基于有限元的功率流计算及隔振系统优化设计技术研究

振动功率流法是研究柔性结构动态特性的有效手段,导纳功率流分析法是目前的主要研究方法,由于只能得到极少数简单结构的解析导纳,对于复杂的结构导纳功率流分析法束手无策.有限元动态分析可以解决绝大多数结构的振动问题,目前大多数有限元动态分析主要集中于模态分析、位移响应分析等.本文从有限元动力方程推导出发,给出了节点频域复数力的表达式,进而给出基于有限元动力分析的功率流计算方法.对一个单梁隔振系统进行理论计算和有限元计算对比,验证了该方法的准确性.最后,基于该方法对隔振器参数和振源布置位置寻优,得到最优参数使传递到基础的振动能量最小.这种方法对大型结构动态设计具有借鉴意义,可应用到工程实际中.

Calculation technique of vibration power flow based on finite element analysis and its application in the isolation system optimization

Vibration power flow is used widely in flexible structures dynamical analysis nowadays.Most calculation methods of vibration power flow are based on the structure mobility analysis.Because only a few kinds of simple structure' analytical mobility can be got by the analytical method, the calculation of power flow of most complex structures is really a nailbiting.On the other hand,finite elment analysis method was applied widely in engineering,but it focus mainly on the calculating of the displace response,modal frequency and modal shapes.New application content was given to finite element analysis method in this paper.A calculation method of vibration power flow based on finite element analysis was brought out.Of this method the complex value of the response force of the node was calculated firstly,and then the vibration power flow was calculated.Check calculation was made on a model which is made up of a beam and an isolated mass.Two methods are used,which are the calculation method based on analytical mobility and the calculation method based on finite element analysis, good accordance was found between them.Finally, an optimization was performed.The best vibration isolator parameters and fixing position were found based on the optimization terminology of ANSYS and the calculation technique of vibration power flow,and the isolation efficiency was greatly improved.The proposed method has considerable reference value in engineering.