【摘要】 本文将球及圆柱形目标的回波声场简化为几何镜反射波与弹性瑞利表面再辐射回波两者的叠加,由此得到了与精确计算结果基本一致的弹性球回波稳态频响曲线,并着重讨论了振幅和相位的频响曲线中极值点(峰、谷)频率与目标共振频率之间的偏离程度,振幅和相位对频率导数的频响曲线中极值点频率与共振频率间的偏离程度,以及这种偏离与目标材料和频率的关系.此外,还讨论了当存在目标以外的干扰回波时,上述频响曲线中极值点频率的稳定性.更多还原

【Abstract】 The echoes of spheies or cylinders are expressed approximatly by the sum of geometrical specular reflective waves and reradiated waves of Rayleigh surface wave.The curves of echo frequency response of spheres are calculated and are compared with precise results.Both agree with each other basically.Then, the deviation between resonant frequencies and frequencies of peaks or valleies of responses, which related to the properties of target and signal frequencies of sound wave is discussed.Finally, the stability of frequencies of extreme value with external disturbances is also discussed.更多还原