环境激励下识别结构模态自然激励-时域分解法  

Natural excitation technique-time domain decomposition algorithm for structural modal identification under ambient excitations

作　　者：钟军军[1] 董聪[1] 

机构地区：[1]清华大学土木工程系,北京100084

出　　处：《振动与冲击》2013年第18期121-125,共5页Journal of Vibration and Shock

摘　　要：针对环境激励下的结构模态参数识别问题,提出识别位移模态新方法—自然激励-时域分解法。将所分析的时域分解算法适用条件由结构自由振动响应信号推广至普遍情况。建立自然激励技术统一模型,证明白噪声激励下结构位移响应的互相关函数经处理可获得与单位脉冲响应函数具有相同数学结构的新函数。该函数满足时域分解算法的推广适用条件。并通过数字滤波器将两者结合建立自然激励-时域分解法,该法用自然激励技术获得新函数替代时域分解算法中结构自由响应函数构造响应时间历程矩阵,可为环境激励下仅有结构有限测点响应识别位移模态提供新途径。用仿真算例验证该方法的合理性及有效性。A novel method called natural excitation technique-time domain decomposition （NExT-TDD） algorithm was presented here for structural modal identification under ambient excitation. The primary principle of time domain decomposition （TDD） algorithm was illustrated, and subsequently its applicable conditions were generalized from a free vibration response signal to more common situations. The unified theoretical model of natural excitation technique （NEXT） was proposed, and then it was proved that a new function defined with structural displacement cross-correlation functions under white noise excitations has the same mathematical structure as that of an impulse response function and consequently it satisfies the generalized applicable conditions of TDD algorithm mentioned above. Then, the NExT-TDD algorithm combining NExT with TDD using digital filters was presented to identify modes of a structure subjected to ambient excitations. The results of example simulations verified the effectiveness of the proposed method.

关 键 词：模态识别 环境激励 时域分解算法 互相关函数 自然激励技术 自然激励-时域分解法 

分 类 号：TU311.3[建筑科学—结构工程]