中文摘要：

为了研究超声导波无损检测的技术核心,利用分向半解析有限元法对矩形杆中超声导波的频散曲线进行计算,求解了几种不同尺寸、不同物理参数的矩形杆中超声导波的相速度和群速度曲线.通过对比得出分向半解析法能够精确求解矩形杆中导波的频散特性;几何尺寸和材料参数的变化对不同导波模态的影响并不相同.最后,搭建试验装置,对具体模型进行试验验证,进一步验证了计算方法的准确性.

英文摘要：

Dispersion curves provide the fundamental information to describe the propagation of elastic waves through a structure. The directional semi-analytical method combined analytical approach with numerical method is very efficient in solving complex problems. In this paper,dispersion relations for three-dimensional waveguides with rectangular cross-section are proposed by using directional semianalytical method. Results show that a rectangular unit can be used to compute the dispersion curves for rectangular-rod. Geometric and physical parameters can affect the dispersion curves,and the influence on different modes is different. Finally,the proposed method is proven by the experiment.