基于响应面法的大型机械传动系统扭转振动可靠性分析

Torsional vibration reliability analysis of large transmission system based on response surface method

对传动系统扭转振动有限元模型应用LANCZOS迭代方法计算固有频率,用MATLAB调用NASTRAN进行迭代,在参数的整个设计空间范围内利用回归分析技术以显式的响应面模型逼近特征量与设计参数间复杂的隐式函数关系。选择较难确定或随时间变化的且对响应特征较为敏感的模型参数作为响应面输入参数,从输入参数的正态分布中抽取样本,利用响应面函数计算样本点的响应值,拟合出响应固有频率值的正态分布。根据工作转速给出传动系统工作频率的分布情况,从而根据可靠性分析方法计算出在模型参数不确定前提下系统不发生共振的可靠度。

By applying LANCZOS iterative method, the natu ral frequencies of the torsional vibration FE model of a transmission system was calculated. Through calling NASTRAN by MATLAB to carry out iteration, within the entire design space, the response sur face model indicated by applying regression analysis technology was used to approach the complicated implicit function relation between characteristic quantity and design parameters. The model parame- ters that is much more difficult to determine or time dependent, and much more sensitive to the response characteristics was selected as input parameters of response surface. By extracting the sample from normal distributions of the input parameters and by using the re sponse values of the response surface calculated sample points, the normal distributions of natural frequencies were obtained. The dis tribution condition of operating frequency of the transmission system was given according to the operating speed, and the reliability that the resonance does not occurs in the system under the precondition that the model parameter is not correct can be calculated based on the reliability analysis method.