基于频响函数的逆子结构方法误差分析  

Error Analysis of Inverse-Substructuring Method Based on Frequency Response Function

作　　者：傅苗苗 王军[1,2,3] 卢立新[1,2] 姜咪 FU Miao-miao;WANG Jun;LU Li-xin;JIANG Mi(School of Mechanical Engineering,Jiangnan University,Wuxi 214122,China;Key Laboratory of Advanced Food Equipment Manufacturing Technology of Jiangsu Province,Jiangnan University,Wuxi 214122,China;Shantou Dongfeng Printing Co.,Ltd.,Shantou 515064,China)

机构地区：[1]江南大学机械工程学院,江苏无锡214122 [2]江南大学江苏省先进食品装备制造技术重点实验室,江苏无锡214122 [3]汕头东风印刷股份有限公司,广东汕头515064

出　　处：《包装工程》2021年第23期141-145,共5页Packaging Engineering

基　　金：国家一流学科建设轻工技术与工程(LITE 2018-29);国家自然科学基金(51205167);江苏省自然科学基金(BK20151128)。

摘　　要：目的通过分析随机误差在基于试验频响函数(FRFs)的逆子结构分析方法中的传递,得出随机误差对预测结果的影响规律,为基于逆子结构方法分析复杂结构的动态特性提供参考价值。方法对获得的系统频响函数施加不同程度(1%,5%,10%)的随机误差,对比分析各个耦合系统频响函数对预测子结构频响函数的影响。结果对耦合系统频响函数施加随机误差后,采用逆子结构方法对耦合系统解耦后预测的子结构频响函数严重偏离真实值,尤其是共振频率附近,所施加的随机误差在预测子结构频响函数中甚至被放大了数十倍,导致预测结果不可靠;且耦合系统耦合点处的频响函数对预测结果的影响最大。结论通过分析明确了系统频响函数所携带的随机误差对预测结果的影响规律,且这些误差将随着矩阵的求逆运算被放大,且交叉耦合系统频响函数对预测结果的影响最为显著。The work aims to study the influence laws of random errors on the prediction results by analyzing the transmission of random error in the inverse-substructuring analysis method based on the experimental frequency response functions(FRFs),so as to provide reference value for analysis of dynamic characteristics of complicated structures based on inverse-substructuring method.Different degrees of random errors were applied to the obtained system frequency response function,and the influence of each coupled system frequency response function on the predicted substructure frequency response function was compared and analyzed.After random error was applied to the coupled system frequency response function,the predicted substructure frequency response function after decoupling of the coupled system by the inverse-substructuring method seriously deviated from the true value,especially near the resonance frequency,and the applied random error was even magnified dozens of times in the predicted substructure frequency response function,resulting in unreliable prediction results.The frequency response function at the coupling point of the coupled system had the greatest influence on the prediction results.Through the analysis,it is clear that the random errors carried by the system frequency response function have an influence on the prediction results,and these errors will be amplified along with the matrix inversion operation,and the cross-coupled system frequency response function has the most significant influence on the prediction results.

关 键 词：频响函数 随机误差 矩阵求逆 

分 类 号：TB485.3[一般工业技术—包装工程]