为研究以 Wigner-Ville 分布的交叉项作为指标进行损伤识别效果，探究完整的提取交叉项方法，通过对二重余弦信号的 Wigner-Ville 分布推导，获得主项与交叉项的位置关系及交叉项震荡特性；据此设计相应的提取方法，将Wigner-Ville 分布中各频率段正负能量分别沿时间轴积分，将正负能量之和绝对值作商，通过设定阈值进行筛选获得交叉项能量分布；以工程实例为研究对象，通过对比无、有损状态下对应测点交叉项能量差的突异点识别损伤位置与程度。试验结果表明，交叉项可作为损伤识别指标，且效果显著。%In order to investigate the effectiveness of using the cross terms of Wigner-Ville distribution to identify damage,a complete extraction of cross terms was explored.Through the derivation of Wigner-Ville distribution of a double cosine signal,the position relationship between main terms and cross terms,their concussion characteristics were obtained,and an extraction method was proposed:For the method,(1 )the positive and the negative energy of each frequency band in Wigner-Ville distribution were integrated,respectively along the time axis;(2)the absolute value of negative energy was used to divide the positive one and a threshold was set for filtering and obtaining the energy distribution of the cross terms.An application was used to validate the method.The cross terms'energy difference of the observation point under non-damaged and damaged status were compared to determine the location and extent of damage. The result showed that the cross terms can be used as an effective damage identification index.
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