摘要
利用多自由度动力学原理对频域载荷识别方法进行分析,对传递函数病态性进行了研究,分析了动态载荷识别方法中响应点位置对传递函数病态性及载荷识别结果的影响。为降低载荷识别误差特别是结构共振频率下的识别误差,基于传递函数的相干分析定义了传递函数相干因子,并提出以最小传递函数相干因子为目标的动态载荷识别位置优化的传递函数相干法。仿真及实验证明了该法能够减小载荷识别误差,提高识别效率,能够有效识别出汽车驾驶室的动态载荷。
Dynamic force identification from structural response is necessary when direct measurement is impossible.Frequency-domain force identification is widely researched.This approach is to determine the frequency response function（FRF） matrix,measure the responses on structure,and calculate the dynamic forces.This approach has been proven to be effective.However,the accuracy of this approach is often influenced by the inversion of an ill-conditioned FRF matrix especially at the frequency of structural resonances.To solve the problem,firstly this paper analyses how the locations of responses influence the illness of FRF matrix and the accuracy of force identification.Then a new method based on FRF coherence analysis is proposed to optimize spatial distribution of response locations.Compared with two other methods in reference this approach is more effective but involve less computational efforts.The error reduction in force determination is found to be significant in numerical simulations on a simple plate and in a cab experiments.
出处
《振动工程学报》
EI
CSCD
北大核心
2011年第1期14-19,共6页
Journal of Vibration Engineering
基金
北京市科技计划项目(D101106047510001)
汽车噪声振动与安全技术国家重点实验室2011年度开放基金项目资助
关键词
频域
载荷识别
传递函数相干法
病态
相干因子
frequency-domain
force identification
coherence analysis method
ill-posed problem
coherence factor
