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对粘接结构进行超声导波无损检测与评估是一个有挑战性的前沿性课题.针对此问题,研究了SH_0导波在界面为理想连接的三层板状粘接结构中传播时的相位变化情况.首先基于波传播的控制方程,建立了粘接结构中反射和透射SH_0导波相对于入射SH_0导波的相位差解析模型.然后利用数值模拟计算了铝/环氧树脂/铝粘接结构中反射和透射SH_0导波的相位差曲线.最后分析了入射角度和频厚积的变化对反射和透射SH_0导波相位差的影响.结果表明,对于具体的粘接结构,反射和透射SH_0导波在其中传播时的相位差变化主要依赖于入射角度、频率等参数.在特定的频厚积下,当声波水平入射时,反射和入射SH_0导波同相位.无论入射角度为多大,随着频厚积的增大,反射SH_0导波的相位差曲线均会产生周期性谐振.对于透射SH_0导波,当声波垂直入射时,其相位差曲线的改变无规律可循;但是随着入射角度逐渐增大,透射SH_0导波的相位差曲线逐渐变规则.所得结果可为实验时研究板状粘接结构中SH_0导波的传播特性以及提取SH_0导波回波中的有用信息和定位提供一定的理论指导.
It is a challenging frontier subject to conduct ultrasonic guided wave non-destructive testing and evaluation of bonded structure.In order to solve this problem, the phase change of SH_0 guided wave in three-layer plate-shaped bonding structure with ideal interface is studied The analytical model of the phase difference of the reflected and transmitted SH 0 guided waves with respect to the incident SH 0 guided wave is established based on the governing equations of wave propagation.And then the numerical simulation of the aluminum / epoxy / aluminum bonding structure The phase difference between the reflected and transmitted SH_0 guided waves was analyzed.Finally, the effects of the incident angle and the frequency-thick product on the phase difference of the reflected and transmitted SH_0 guided waves were analyzed.The results show that for the specific bonding structure, The phase difference of the wave propagates in it mainly depends on the parameters such as the angle of incidence and the frequency, etc. Under a certain frequency-thick product, when the sound wave is incident on the horizontal plane, the SH0 guided wave is reflected and incident on the same phase regardless of the incident angle The increase of frequency-thick product and the phase difference of reflection SH_0 lead to periodic resonance. For the SH_0 guided wave, when the sound wave is incident perpendicularly, the change of the phase difference curve is irregular. However, With the incident angle increasing, the phase difference curve of SH_0 guided wave gradually becomes regular, and the obtained results can be used to study the propagation characteristics of SH_0 guided wave and the useful information in SH_0 guided wave echo And positioning to provide some theoretical guidance.