【摘要】 鉴于信号提取位置的不确定性,研究了信号提取位置对损伤识别的影响.对管道进行数值模拟,提取前两阶径向和切向位移模态.对轴向节点的径向位移模态进行小波变换,小波系数的模极大值反映了损伤的轴向位置;继续对环向节点的切向模态进行小波变换,通过模极大值来识别环向损伤位置;最后讨论了轴向损伤处节点径向位移的小波系数模极大值变化规律.结果表明:两步法可以有效识别损伤位置,轴向位置不含损伤时位移模态的小波系数能显示损伤的轴向位置但小波系数有所减少.更多还原

【Abstract】 Due to uncertainty of location acquiring signal,the effect of acquired signal location on the damage detection is investigated.The first two order radial and tangent displacement modes of pipe are acquired.The sudden change of wavelet coefficient,which is transformed by radial displacement mode of axes nodes with bior wavelet,shows the axes location of damage.The tangent displacement mode of the circular mode at the axes damage location is analyzed and transformed by the same family wavelet.The circular damage location can be determinated by using the same procedure.The results shown that the two-stage procedure enables the identification of correct damage location.When there is no damaged axes node,the wavelet coefficients of axes nodes can identify the damage location and can be decreased in number.更多还原