基于PZT波传播法的钢-UHPC桥面板脱空识别研究

Detection of the Steel-UHPC Composite Slabs with Debonding Defect Using Wave Propagation Method with Piezoceramics

为了测试PZT波传播法对钢-UHPC轻型组合桥面板界面脱空识别的有效性,分别进行了数值分析和试验进行脱空识别。利用ANSYS对钢-UHPC薄板不同厚度脱空进行了数值模拟,分析了不同激励电压幅值和频率下信号波幅值衰减程度,结果表明激励电压与波传播幅值呈线性关系,激励频率对波的能量损耗有较大关系,得到试验测试敏感频段范围;浇筑了具有不同厚度脱空的钢-UHPC薄板,并在试件脱空处两侧对称粘贴PZT,使用信号发生器产生激励信号,由接收仪器测量压电信号,通过分析信号能量、幅值并引入损伤指数。分析表明损伤指数随着脱空厚度增大而增大,且可初步确定损伤大小。PZT波传播法为今后测试钢-UHPC界面粘结状况提供了有效方法。

The numerical simulation analyses and experimental tests are presented in the study to effectively identify the local debonding of steel-UHPC composite slabs based on wave propagation method using piezoceramics sensors.The steel-UHPC composite slab with different debonding degrees is simulated and analyzed using ANSYS,considering the influence of different amplitude and frequency of excitation voltage.The results indicate that excitation voltage is directly proportional to the amplitude of wave propagation and the excitation frequency has impact on the energy loss of wave signal.Different thickness of debonding defect is proposed and tested with a set of steel-UHPC composite slabs specimens.PZT patches were symmetrically pasted on the predetermined locations of the specimen as actuators and sensors,and the excitation signal generated by signal generator is received by signal receiver.The debonding defects of the specimen are detected based on the wavelet package energy and the measured signal amplitude of the PZT patches.Results show that the damage index was influenced by the thickness of debonding defect,which indicates that the proposed method is effective for the monitoring of debonding defect of steel-UHPC composite slabs.