使用应变模态和遗传算法的有限元模型修正方法  

Finite Element Model Updating Using Strain Mode and Genetic Algorithm-Based Method

作　　者：展铭 郭勤涛[1] 岳林[1] 张保强 ZHAN Ming;GUO Qintao;YUE Lin;ZHANG Baoqiang(College of Mechanical and Electrical Engineering,Nanjing University of Aeronautics and Astronautics Nanjing,210016,China;College of Aeronautics and Astronautics,Xiamen University Xiamen,361005,China)

机构地区：[1]南京航空航天大学机电学院,南京210016 [2]厦门大学航空航天学院,厦门361005

出　　处：《振动．测试与诊断》2018年第5期974-978,1081,1082,共7页Journal of Vibration,Measurement & Diagnosis

基　　金：国家自然科学基金资助项目(51275240;51505398;U1530122);航空科学基金资助项目(20150968003)

摘　　要：提出了采用应变模态置信度为待修正响应特征的有限元模型修正方法。应变模态置信度是评价有限元仿真与试验测试结果相关性的方法,可以为模型修正提供全局的频率误差信息和局部的应变相关性信息。首先,介绍了应变模态和有限元模型修正的相关理论方法;然后,以某航空加筋壁板结构为对象,通过仿真分析和"仿真试验"获得结构的应变模态频率以及对应的应变振型,进一步计算频率误差和应变模态置信度误差;最后,基于两种误差构造模型修正的目标函数,采用遗传算法对目标函数进行优化,修正结构中的待修正参数,并将修正后参数代入模型,验证所提方法的正确性和有效性。结果表明:所采用的方法获得的修正后有限元模型具有复现修正响应特征的能力,并且对于未修正频段内的响应也具有较好的预测能力。Based on strain modal assurance criterion,a model updating method is proposed.Strain modal assurance criterion,on one hand,is a satisfactory approach to evaluate the correlation between finite model simulation and experiment.On the other hand,strain modal assurance criterion offers global frequency error and local mode shape error for model updating.The basic theory of strain mode and finite element model updating is briefly introduced.Then,take a stiffened structure as example,the process of model updating based on strain mode is illustrated.Firstly,strain modal frequencies and mode shapes are obtained from simulation and experiment,respectively.And then,modal assurance criterion of strain modes and error of modal frequencies are calculated.The objective function for model updating is constructed based on above errors and unknown parameters are estimated utilizing genetic algorithm.Finally,the estimated parameters are substituted into the finite model to validate the accuracy and effectiveness.The results show that:the proposed method can reproduce the response in the updating domain and have an excellent ability to predict the response outside the updating domain.

关 键 词：应变模态 模态置信度 模型修正 遗传算法 加筋壁板 

分 类 号：TH113[机械工程—机械设计及理论] O327[理学—一般力学与力学基础]