【摘要】 提出了互相关函数幅值向量的概念,阐述了形成CorV的基本原理。并且证明了结构在频率成分一定的随机激励下,CorV只与结构的频率响应函数有关,规范化后的CorV具有固定的形状,从而CorV可以看作结构在这种激励下的一种固有特性。因此定义互相关函数幅值向量置信度判据来标定结构CorV的变化,以此来识别结构的损伤。文中还研究了测量噪声对CorV的影响,当信噪比(SNR)或损伤增大到一定的程度时,测量噪声的影响可以忽略。因此用CorV来检测结构损伤具有工程应用上的可行性;同时发现无论有无测量噪声,损伤结构与完好结构CorV之间的CVAC随着损伤程度的增大而单调下降,因此CorV也可用来判定损伤的程度。CorV具有固有振型的特点,但无需进行模态测试,而是直接由结构在随机激励下的时域响应信号获得,因此,基于CorV的结构损伤检测方法为环境激励下的结构损伤检测研究提供了理论基础。更多还原

【Abstract】 The paper concept of correlation function amplitude vector(CorV) to detect structural damage.It also describes the principle and formation process of CorV are also described and verifies that under random excitation and with a specific frequency spectrum,the CorV is related only to the frequency response function of a structure and that the normalized CorV has a specific shape.The CorV can be treated as a kind of "generalized mode shape" of the structure under this excitation.Therefore,the correlation function amplitude vector assurance criterion(CVAC) is proposed to quantify the change of CorV and is applied to detect damage of the structure.The effects of measuring noise on the CorV are also studied,and it is found that when the signal and noise ratio(SNR) or the damage severity is large enough,the effect of measuring noise can be neglected.Meanwhile,the paper discovers that the CVAC of the CorV of the damaged and intact structures monotonously decreases with the increasing of damage degrees no matter whether the noise exists or not.Thus the CorV can also be used to determine damage severity.The CorV is obtained directly from the measured time domain response signals of the structure under random excitation because it has the characteristics of mode shape and no model test is needed.The present approach can be applied to structural damage detection under ambient excitation.更多还原