T-Stress Values During Fracture in Wedge Splitting Test Geometries: A Numerical Study

Abstract

The paper is focused on a detailed numerical analysis of the stress field in specimens used for the wedge splitting test (WST), which is a convenient alternative to the classical bending and tensile tests within the area of determination of the fracture-mechanical parameters of quasi-brittle building materials, particularly cementitious composites. The near-crack-tip stress field in the WST specimen is described by means of constraint-based two-parameter fracture mechanics in the paper. Particular attention is paid to the influence of usual variants of boundary conditions used for this kind of testing procedure on the stress field in the cracked body. The next part of the paper aims at investigation of how much the detailed description of the near-crack-tip stress field obtained by applying the two-parameter fracture mechanics approach is then utilizable for an estimation of the size and shape of the non-linear failure zone in quasi-brittle materials, i.e. the fracture process zone (FPZ). The results obtained with regard to the near-crack-tip stress field approximation are compared with data taken from the literature. An attempt is made to exploit the estimation of the FPZ extent within the determination of fracture-mechanical characteristics of cementitious composites.