单独利用响应数据进行模态分析  

Modal Analysis from Response-only

作　　者：郑敏[1] 申凡[1] 史东锋[1] 陈怀海[1] 

机构地区：[1]南京航空航天大学,南京210016

出　　处：《中国机械工程》2006年第4期405-409,共5页China Mechanical Engineering

基　　金：国家自然科学基金资助项目(50205012);航空基金资助项目(01152059);民航基金资助项目(Y0466-MH)

摘　　要：针对工程实际中模态分析方法存在的不足,提出两种单独利用实测响应数据的互相关模态识别法,即互相关差分模型法和互相关频域识别法。根据脉冲响应函数同响应间的互相关函数具有相似的表达形式,在时域中采用基于相关函数的互相关差分模型提取模态参数,在频域中采用基于互功率谱密度函数的互相关频域识别法对结构进行模态识别。对这两种方法进行了理论推导,并以一飞机模型为例进行了试验验证,将结果同适调激振法所得结果作了比较,证明所述两种方法都能够较好地仅利用实测响应进行模态辨识。Focusing on some disadvantages of modal analysis techniques in engineering, two modal identification methods based on cross--correlation from response-only were proposed, they arc difference model and frequency-domain modal parameter extraction. According to the same expression between the impulse response function and the cross--correlation function, modal parameters were extracted by difference model with cross--correlation functions in time--domain and by frequency- domain modal identifications with cross-power spectrum functions in frequency-domain. Theoretical derivations about both methods were done at first, then experiments were completed with an airplane model to verify them. The results from the outlined techniques were compared with those from the pure mode excitation technique and the experimental results show that the proposed methods can do modal identification from response-only well.

关 键 词：工作环境 大型结构 工作模态 模态分析 

分 类 号：TB122[理学—工程力学]