弱连接界面弹性波波动规律研究

实验表明，自然界的界面既非连续也非完全不连续，绝大多数可以用柔度系数表征为弱连接界面．当内部微裂隙和不均匀体是波场的主导影响因素时，即使在内部完好粘结的界面层存在的条件下，波场特征能够反映微裂隙的影响，此时有效模量理论仍能刻画波场的宏观特征；由于界面含有物质不同，不管是尺度较大的界面还是尺度较小的微细裂隙，都表现出弱连接界面的特性，当界面以不连续特征为主导时，仍用有效模量理论会导致失真或错误；在实验基础上研究了弹性波在不同介质中通过弱连接界面时的波动规律，推导了诸如弹簧模型、麦克斯韦模型的反射系数与透射系数，并对横波垂直入射粘性不连续界面时透射系数与频率的关系、纵波垂直入射粘性不连续界面时反射和透射系数与时间延迟和频率的关系进行了总结分析．

The Propagating Rule Study on Elastic Wave Across Loosely-boned Interface

It shows by experiments that interfaces in the nature are not continuity or discontinuity, most of them are loosely-boned interfaces which can be expressed by flexible coefficients. When tiny fractures and non-uniformity body are main influence factors, even though at conditions of the existence of inside well-boned interfaces, characteristics of wave propagation can reflect effect of tiny fractures, here theory of effective modules can still describe macro-characteristics of wave field. Because of substance different in the interfaces, either large scale interfaces or small scale tiny fractures, they put up characteristics of loosely-boned interfaces, when interfaces show dominant characteristics of discontinuity, distortion or mistake can be caused by application of theory of effective modules. Propagating rules of elastic wave cross loosely-boned interfaces in different media are studied on the basis of experiments, reflect and transmit coefficients of spring model and Maxwell model are derived, analysis is made for relations of transmit coefficients and frequency when transverse wave vertically cross viscosity discontinuity interfaces, and for relations of reflect and transmit coefficients and time delay or frequency when wave P vertically cross viscosity discontinuity interfaces.