基于Sobol’法的车身噪声传递函数全局灵敏度分析

Global Sensitivity Analysis of Autobodies' Noise Transfer Functions Based on Sobol' Method

针对局部灵敏度分析方法不能考虑参数的概率分布、不能适用参数大范围变化及分析各参数之间交互作用等局限,将Sobol’全局灵敏度分析法引入到汽车噪声传递函数的灵敏度分析中。Sobol’法将函数f(x)分解成2n项递增项之和,通过采样计算模型响应的总方差及各偏方差,以求得灵敏度,从而有效避免了局部灵敏度分析方法的缺陷。以某型轿车为例,在建立声固耦合有限元模型的基础上,计算出从悬置点到驾驶员右耳处的车身噪声传递函数,并运用Sobol’法分析出相关板件厚度的一阶全局灵敏度及总体全局灵敏度值,从而甄别出对驾驶员耳旁声压单独影响较大或交互作用显著的板件,为车身噪声传递函数的优化工作提供指导。应用实例验证了该方法的有效性。

In order to overcome the limitations that the local sensitivity analysis can not consider the probability distribution of the parameters,and is not applicable for the obvious changes of parameters and not suitable to analyze the interaction of various parameters, the Sobol＇ global sensitivity analysis method was introduced into the sensitivity analysis of auto-body＇s noise transfer function herein. The main idea behind Sobol＇ method was to decompose the model function f（x） into sums of increasing items whose dimensionality was as 2n. Then the sensitivities can be determined by sampling the parameters and calculating the total variance and partial variance of the model＇s outputs. It can avoid the weakness of the local sensitivity analysis effectively. Based on the acoustic-structure coupling finite element model, the paper calculated the auto-body＇s noise transfer function from the suspending point to driver＇s right ear. The first and total global sensitivity of the related panels thickness was carried out by Sobol＇ method to discriminate the key factors with strong influences. And according to the guidance of the sensitivity analysis, the auto-body＇s noise transfer function was optimized. The validity of the Sobol＇ method were demonstrated by the results of the applications.