Finite element analysis of fracture behaviour of piezoelectric smart materials

Smart materials with embedded distributed piezoelectric layers as sensors and actuators have been used frequently in engineering over the past few years. Unfortunately, cracks and delaminations, which are typical early damage phenomena in such materials, may result in significant changes of the static and dynamic response of the structure. The main focus of the paper is to investigate and to develop an efficient finite element procedure to model and analyse the fracture behaviour of piezoelectric smart materials. Possible fracture criteria are discussed. A catalogue of multifunctional finite elements with coupled electromechanical fields has been developed, to analyse smart structures. Together with the fracture criterion these finite elements are used to simulate crack and delamination in piezoelectric materials and laminated smart structures. The results indicate that an electric field can either aid or retard crack propagation depending on the direction of the electric load.