The influence of the shape of a saw-cut notch in quasi-brittle 3PB specimens on the critical applied force

Abstract

Values of fracture parameters of quasi-brittle building materials are usually determined from results of tests performed on notched testing specimens. The contribution deals with the influence of various shapes of tips of notches prepared by a diamond saw in three point bending (3PB) specimens. The influence of the notch tip shape on the applied force corresponding to a failure initiation at the notch tip and also on the critical applied force appropriate to the maximal load-bearing capacity of the specimen is studied. Calculations are performed in two finite element method (FEM) systems (ATENA, ANSYS) based on two different approaches to fracture description (Cohesive crack models and LEFM, respectively). The numerical results obtained by both FEM systems are compared. The influence of notch shapes and width is quantified.