Electric and magnetic polarization saturation and breakdown models for penny shaped cracks in 3D magnetoelectroelastic media

Two nonlinear fracture models, i.e., the electric and magnetic polarization saturation (EMPS) and electric and magnetic breakdown (EMBD) models for penny shaped cracks in three-dimensional magnetoelectroelastic media are studied via the extended displacement discontinuity integral equation method. In the EMPS model, the electric displacement and magnetic induction are constant respectively in the planar electric yielding zone and magnetic yielding zone on the original crack plane, whilst in the EMBD model, the electric and magnetic strengths are constant respectively in their planar yielding zones. Under the electrically and magnetically impermeable conditions and uniformly applied mechanical–electric–magnetic loadings on the faces of the penny shaped crack, analytical solutions are derived for the sizes of electric and magnetic yielding zones and the field intensity factors. It is demonstrated that the fracture behaviors can be predicted equivalently by both EMPS and EMBD models even though they are built on two different physical grounds.