基于响应面法的转向架构架结构强度分析

Strength Analysis of Bogie Frame Structure based on Response Surface Method

为了快速准确地评估转向架构架的结构强度,将响应面法和可靠性理论相结合对其进行结构强度分析.运用APDL语言建立转向架构架的参数化模型,并根据标准计算其结构强度.考虑试验设计方法对构架响应面函数精度的影响,分别采用中心组合设计、Box-Behnken设计和三水平全因子设计三种试验设计方法对其进行样本点的选取.利用最小二乘法对试验数据进行拟合,建立构架的多项式响应面函数.基于响应面函数,采用Monte-Carlo方法和应力-强度干涉理论对构架进行结构强度的可靠性分析.研究结果表明:试验设计方法的不同对响应面函数精度的影响较大,通过中心组合设计拟合的响应面函数精度较低,三水平全因子设计相比Box-Behnken设计在拟合精度相似的条件下,计算量较大.三种试验设计方法下,转向架构架的结构可靠度分别为0.97,1和1,表明了响应面函数的精度对准确评估构架的可靠性具有重要作用,同时为准确评估构架的结构强度提供了理论指导.

In order to evaluate structural strength of bogie frame quickly and accurately,the response surface method and the reliability theory are combined to analyze the structural strength. The parameterized model of the bogie frame was established by APDL language,and its structural strength was calculated according to the standard. Considering the influence of the experiment design method on the accuracy of the response surface function,central composite design,Box-Behnken design and 3-level factorial design are adopt to select sample points. Using the least square method to fit the test data,the polynomial response surface function of the framework was established. The Monte-Carlo method and the stress-intensity interference theory were used to analyze the structural strength of the frame based on the response surface function. The results show that the difference of experiment design methods has great influence on the accuracy of the response surface function.The accuracy of the response surface function fitted by the central composite design is low. Compared with the 3-level factorial design,the Box-Behnken design has a large amount of computation when the fitting accuracy is similar. The structural reliability of bogie frame is 0. 97,1 and 1 under three experiment design methods,which indicates that the accuracy of the response surface function plays an important role in accurately evaluating the frame reliability,and provides theoretical guidance for accurately evaluating the structural strength of a frame.