矩形表面波探头声场的高斯声束叠加法

利用矩形压电晶片和有机玻璃楔块折射可激励出超声表面波,广泛用于固体近表面缺陷检测和材料特性测量.由于描述表面波三维声场的理论方法还鲜有报道,因而主要采用简化的表面波二维声场模型来定量分析这类问题.高斯声束模型近些年被广泛应用于解决超声体波传播的各种复杂问题,然而,目前还没有将其扩展应用到超声表面波的声场的计算中.通过结合表面波格林方程和矩形换能器的高斯声束模型,推导出基于高斯声束叠加的表面波三维声场解析解.进一步,将该方法与点源叠加的数值解进行了分析比较,计算结果表明表面波声场的高斯声束叠加方法在具有较好计算精度的同时,还具有更快的计算效率.

Multi-Gaussian beam model for ultrasonic surface waves with angle beam rectangular transducers

Rayleigh waves propagating in an elastic surface are commonly used for the near surface flaw detection and material characterization. However, unlike the bulk wave case, there are seldom three-dimensional models to be provided for the Rayleigh waves. In the past decade, multi-Gaussian beam models have been gradually developed and perfectly applied to solve many complicated propagation problems of bulk waves. However, up to date they have not been extended to the simulation of the Rayleigh waves. By combining the Rayleigh wave Green function and the multi-Gaussian beam model, a three-dimensional Rayleigh wave model is presented to calculate the beam fields radiated from a rectangular transducer mounted on the Lucite wedge. Furthermore, some simulation results of the provided method are compared to those of a more exacted point source model. It is shown that the multi-Gaussian surface wave model has good capability in both computational accuracy and efficiency.