Finite element analysis of piezoelectric corner configurations and cracks.pdf

Engineering Fracture Mechanics 74 (2007) 1511–1524 /locate/engfracmechFinite element analysis of piezoelectric corner configurations and cracks accounting for different electrical permeabilities Meng-Cheng Chen *, Xue-Cheng Ping School of Civil Engineering, East China Jiaotong University, Nanchang, Jiangxi 330013, PR China Received 24 January 2006; received in revised form 27 July 2006; accepted 7 August 2006 Available online 1 November 2006Abstract Based on eigenfunctions of asymptotic singular electro-elastic fields obtained from a kind of ad hoc finite element method [Chen MC, Zhu JJ, Sze KY. Finite element analysis of piezoelectric elasticity with singular inplane electroelastic fields. Engng Fract Mech 2006;73(7):855–68], a super corner-tip element model is established from the generalized Hellinger–Reissner variational functional and then incorporated into the regular hybrid-stress finite element to determine the coefficients of asymptotic singular electro-elastic fields near a corner-tip. The focus of this paper is not to discuss the well-known behavior of electrically impermeable and permeable (usually it means fully permeable, hereinafter the same) cracks but analyze the limited permeable crack-like corner configurations embedded in the piezoelectric materials, i.e., study the influence of a dielectric medium inside the corner on the singular electro-elastic fields near the corner-tip. The boundary conditions of the impermeable or permeable corner can be considered as simple approximations representing upper and lower bounds for the electrical energy penetrating the corner. Benchmark examples on the piezoelectric crack problems show that present method yields satisfactory results with fewer elements than existing finite element methods do. As application, a piezoelectric corner configuration accounting for the limited permeable boundary condition is investi- gated, and it is found that the limited permeable assumption is necessary for corners with very smal