ACTA MECHANICA SOLIDA SINICA, Vol. 15, No.2, June 2002 Published by HUST, Wuhan, China ISSN 0894 - 9166 SCATTERING OF LOVE WAVES BY AN INTERFACE CRACK BETWEEN A PIEZOELECTRIC LAYER AND AN ELASTIC SUBSTRATE" Gu Bin Yu Shouwen Feng Xiqiao ( Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China) Mai Yiu-Wing ( School of AerospaceMechanical and MechatronicEngineering, The Universityof Sydney, N. S. W. 2006, Australia) AKgI'RACT The scattering of Love waves by an interface crack between a piezoelectric layer and an elas- tic substrate is investigated by using the integral transform and singular integral equation techniques. The dy- namic stress intensity factors of the left and the right crack tips are determined. It is found from numerical calculation that the dynamic response of the system depends significantly on the crack configuration, the ma- terial combination and the propagating direction of the incident wave. It is expected that specifying an appro- priate material combination may retard the growth of the crack for a certain crack configtmation. KEY WORDS dynamic stress intensity factor, Love wave, piezoelectric layer, interracial crack, integral transform, singular integral equation I . INTRODUCTION Advanced structures with intelligent self-monitoring and self-control capabilities are increasing due to the rapid development of smart space systems and micro-electromechanical structures. Piezoelectric materials have found extensive applications in such smart devices as electromechanical sensors, actua- tors and transducers by virtue of the intrinsic electromechanical coupling effects. Inherent weakness of piezoelectric ceramics is their brittleness in mechanical aspects and behavior. In most of their applica- tions, piezoelectric crystals, ceramics and composites are exposed to severe mechanical and electrical loading conditions, which may result in structural fracture or failure. Meanwhile, piezoelectric materi- als usually have some initial defects such as mic.ro-cracks, micro-voids and inclusions, which may also bring about the failure of struc~res. To improve the performance and to predict the rehable secure life of piezoelectric systems, it is of significance to theoretically analyze and accurately describe the damage and fracture behavior of piezoelectric materials from the perspective of coupled effects of mechanical and electrical fields N-a] . Piezoelectric components are liable to sustain dynamic loads in service since they are often used to Project supported by the National Natural Science Foundation of China (No. 19891180), the Fundamental Re- search Foundation of Tsinghua University (JZ 2000.007) and the Fund of the Education Ministry of China. Received 18 September 2001 ; revision received 29 March 2002.