EI / SCOPUS / CSCD 收录

中文核心期刊

水中有限弹性柱的回波结构

ECHO STRUCTURE OF SOUND SCATTERING BY A FINITE ELASTIC CYLINDER IN WATER

  • 摘要: 本文研究短脉冲从有限弹性圆柱上的回波结构。强调指出,在倾斜入射情况下回波仍然包括两类散射波:(1)几何散射波,即棱角波。(2)弹性散射波,即与柱体的弹性有关的波。几何散射波是由柱体的几何不连续性反射的波,它基本上与物体的材料无关,利用Kirchhoft近似可以导出刚性柱棱角波的完整表示式。倾斜入射情况下的弹性散射波不同于无限长柱的环绕波。实验观测到两类由弹性表面波的再辐射产生的回波:径向表面反向散射波和纵向表面反向散射波。这是根据回波的出现时间和倾角,以及空气中的对比实验而辨认的。它们是由沿径向和纵向反向传播的Rayleigh波的再辐射产生的。

     

    Abstract: This paper investigates the echo structure of a short pulse from a finite solid elastic circular cylinder.It is emphasized that in the case of oblique incidence the echoes still include two kinds of the scattering waves:(1).Geometrical scattering waves,namely corner waves.(2).Elastic scattering waves,i.e.the waves related with the elasticity of the cylinder.The geometrical scattering waves are the waves reflected from discontinuities of the cylinder,and essentially independent of the material of the cylinder.Using Kirchhoff approximation the whole representation of corner waves from rigid cylinder has been derived.In the case of oblique incidence the elastic scattering waves differ from the circumferential waves for an infinite cylinder.Two sorts of echoes caused by the reradiation of elastic surface wave have been observed in experimentation:the radial surface backscattering wave and the longitudinal surface backscattering wave.They can be identified according to the arriving time and appearing angle,and the results of a comparable observation in the air.They are caused by the reradiation of Rayleigh wave propagating along the radial surface or the longitudinal surface in the backward direction.

     

/

返回文章
返回