曲线坐标系下孔隙介质圆柱纵向表面波的传播特性

为了研究孔隙介质圆柱纵向表面波的传播规律，分析其频散和衰减特性，在正交曲线坐标系下建立了表面波的频散方程，通过数值计算得到频散曲线，将纵向导波最低模态与表面波进行对比，并分析了曲率半径及孔隙参数对表面波频散和衰减的影响。结果表明，当频率足够大时，导波最低模态的频散曲线与表面波近似；在同一频率下，表面波的相速度随曲率半径的增大而增大，随孔隙度的增大而减小；表面波的衰减随孔隙度的增大而增大。研究结果为开展孔隙介质圆柱结构的超声无损评价提供了一定的理论参考。

Propagation characteristics of longitudinal surface wave in porous media cylinder in curvilinear coordinate system

To research on the propagation characteristics of longitudinal surface wave in porous media cylinder, the dispersion equation of surface wave is established in orthogonal curvilinear coordinate system combined with Biot theory. Through numerical calculation, the dispersion curve has been obtained. The lowest mode of guided wave is compared with surface wave, and the effects of curvature radius and porosity on dispersion and attenuation of surface wave are analyzed. The results show that when the frequency is large enough, the dispersion curve of the lowest mode of guided wave is similar to that of surface wave; At the same frequency, the phase velocity of surface wave increases with curvature radius, decreases with porosity, and the attenuation of surface wave increases with porosity.