EM388F Term Paper: Discussion of fracture criterions with the crack surface boundary conditions of piezoelectric materials

Abastract: The fracture criterions of piezoelectric materials are different from those of common brittle and ductile materials due to their particular electrical-mechanical responses under the electrical-mechanical loading fields.There have five different fracture criterions for the crack in piezoelectric materials: (1) maximum loop stress; (2) total energy release rate (TERR); (3) mechanical strain energy release rate (MSERR); (4) local and global energy release rate only coming from the electrical yielding; (5) influence of mode-mixity on fracture. Using of these criterions is associated with the selections of the electrical boundary conditions including: (1) impermeable and mechanical traction free cracks surface; (2) permeable and mechanical traction free cracks surface; (3) exact electrical boundary and traction free cracks surface.In this term paper, two criterions (TERR and MSERR) under various mechanical and electrical loading fields for the impermeable crack surface and the permeable crack surface are discussed and for the impermeable crack, the mechanical strain energy release rate is reasonable while for the permeable crack, the total energy release rate is more reasonable.

Reference:

Chen YH and Lu TJ, 2003. Cracks and fracture in piezoelectrics. Advance in Applied Mechanics, 39:121–213.

Liu Q. and Chen YH, 2002. Energy analysis for permeable and impermeable cracks in piezoelectric materials. International Journal of Fracture, 116: 15-20.

Xu XL and Rajapakse R.K.N.D, 2001. on a plane crack in piezoelectric solids. International Journal of Solids and Structures, 38: 7643-7658.