Mode II fracture of an elastic-plastic sandwich layer

Dear iMechanicians,

Please find below a paper, co-authored with Ivan Cuesta and Norman Fleck, on the mode II fracture of elastic-plastic sandwich layers. The paper is part of the special issue in the Journal of Applied Mechanics dedicated to John Hutchinson's 80th anniversary and the Century Fracture Mechanics Summit.

https://asmedigitalcollection.asme.org/appliedmechanics/article/doi/10.1115/1.4044898/975667/Mode-II-fracture-of-an-elastic-plastic-sandwich

E. Martínez-Pañeda, I.I. Cuesta, N.A. Fleck. Mode II fracture of an elastic-plastic sandwich layer. Journal of Applied Mechanics, 87(3): 031001

The shear strength of a pre-cracked sandwich layer is predicted, assuming that the layer is linear elastic or elastic-plastic, with yielding characterized either by the J2 plasticity theory or by a strip-yield model. The substrates are elastic and of dissimilar modulus to that of the layer. Two geometries are analyzed: (i) a semi-infinite crack in a sandwich layer, subjected to a remote mode II K-field and (ii) a center-cracked sandwich plate of finite width under remote shear stress. For the semi-infinite crack, the near-tip stress field is determined as a function of elastic mismatch, and crack tip plasticity is either prevented (the elastic case) or duly accounted for (the elastic-plastic case). Analytical and numerical solutions are then obtained for the center-cracked sandwich plate of the finite width. First, a mode II K-calibration is obtained for a finite crack in the elastic sandwich layer. Second, the analysis is extended to account for crack tip plasticity via a mode II strip-yield model of finite strength and finite toughness. The analytical predictions are verified by finite element simulations, and a failure map is constructed in terms of specimen geometry and crack length.