自由度匹配技术在网壳结构损伤识别应用中的比较研究  

COMPARATIVE STUDY OF MODEL MATCH TECHNIQUES USED IN DAMAGE DETECTION ON RETICULATED SHELL

作　　者：刘伟[1] 高维成[1] 孙毅[1] 

机构地区：[1]哈尔滨工业大学航天科学与力学系,哈尔滨150001

出　　处：《振动与冲击》2007年第2期107-111,共5页Journal of Vibration and Shock

基　　金：国家自然科学基金项目(50478030);黑龙江省科技攻关项目(GC04C101)

摘　　要：测试自由度与有限元模型自由度不匹配是损伤识别技术应用于实际工程的最大障碍,动力模型缩聚和特征向量扩充技术是解决这一问题的主要手段。提出了基于剩余模态力和最小秩摄动理论的两阶段损伤识别算法,对几种模型缩聚技术和特征向量扩充技术在网壳结构损伤识别应用中的可行性、优缺点及适用范围进行了比较研究。通过单层短程线网壳结构模型的数值模拟,同时考虑测试噪声影响,实现了测试信息不完备情况下的网壳结构损伤识别。结果表明,本文所提出的损伤识别算法可以识别出网壳结构的单位置刚度损伤,而且利用Guyan静态缩聚法和Guyan扩充法进行自由度匹配后的损伤识别结果非常准确,它们是网壳结构损伤识别应用中模型自由度匹配的最佳选择。Mismatching between the degrees of freedoms(DOFs) of the measurement model and those of the finite element model is the principal drawback when damage detection technique is used to monitor actual civil constructions.Model reduction algorithms and eigenvector expansion algorithms are the special methods to resolve the above problem.The two-step damage detection algorithm based on the residual modal force and the minimum rank perturbation theory is proposed.Some different types of model reduction algorithms and eigenvector expansion algorithms are compared when they have application in damage detection on the reticulated shell.The feasibility,strength and scope of application of each algorithm are introduced.Under the incomplete measurement information,a numerical simulation is deeply conducted for damage detection on the single-layer reticulated shell model. Meantime,the measurement error is taken into account and identification capacity of the proposed algorithm corresponding to damage extent is analyzed.The results show that with the proposed damage detection method the single location damage can be determined.It is feasible for health diagnoses of reticulated shells.Furthermore,the results using Guyan reduction and Guyan expansion algorithms to match the DOFs are of high accuracy.They are the best selection of matching the DOFs of models.

关 键 词：网壳 损伤识别 模型缩聚 特征向量扩充 剩余模态力 

分 类 号：O327[理学—一般力学与力学基础]