基于高频电阻抗信号的结构损伤监测

给出了利用高频电阻抗信号进行结构损伤识别的精确定量分析方法.考察压电片－黏结层－主体结构组成的一个耦合结构系统，主体结构采用一维模型并只考虑轴向振动，引入剪滞模型来描述压电片与主体结构之间的剪力传递，考虑压电片的动力效应，采用传递矩阵法导出了这一耦合结构的系统方程，得到了压电片电导纳的解析表达式.通过算例验证了所给出方法的正确性和有效性.计算结果表明，弱界面对电阻抗信号有较大的影响，利用电导纳的虚部可以清楚地检测到界面的弱黏结；采用电阻抗技术能够很好地识别结构局部的细小损伤.

Damage detection with high-frequency electric impedance signals

High-frequency electric impedance signals(HFEIS) were used for structural health monitoring,and are very sensitive to the early-stage damages of structures.A coupled system of piezoelectric patch-adhesive-main structure was considered.The main structure was modelled as a one-dimensional bar that vibrated longitudinally.A shear lag model was used to describe the shear transmission between piezoelectric patch and main structure.The model accounts for different bonding properties.The equations of dynamic system of the coupled system were derived by using transfer matrix method.The analytical expression for the electric impedance of the piezoelectric patch was obtained. The correctness and effectiveness of the proposed analysis method was verified numerically.Results showed that the interfacial properties have an important effect on the electric impedance signals,and that HFEIS can be feasibly used to detect small and local damages.