Mixed-mode fracture behaviour of refractories with asymmetric wedge splitting test. Part I: Numerical implementation and validation

Abstract

The suitability of asymmetric wedge splitting test (WST) for mode I/II mixed-loading was validated by FE simulation with a three-dimensional heterogeneous continuum FE model. The unsymmetrical strain and stress patterns were observed for mixed-mode loading. Compared with mode I loading of symmetric WST, the introduction of in-plane shear accelerates the crack extension and deviation from symmetry plane with a smaller fracture process zone. Additionally, the asymmetric WST with small, medium and large wedge angles were simulated for sensitivity analysis. With the increasing of asymmetric wedge angle, the recorded vertical load-displacement curves turn from “mild” to “steep”, and the ratio of mode I to mode II fracture energy GI/GII decreases accordingly while the symmetric one has the highest GI proportion. The asymmetric WST with large wedge angle deforms the most at same applied vertical loading displacement, while all WSTs show similar damaged elements amount at the same crack mouth opening displacement.