Fracture Energy Determination of Quasi-Brittle Materials

Abstract

A simple method is proposed for determination of fracture energy of materials exhibiting quasi-brittle behavior during mode I cracking. A series of graphs showing the relationship between the nondimensional peak load and the nondimensional beam size are generated for a three-point beam configuration using a new and computationally efficient finite-element program. The method only requires the measurement of the peak load of a single-size beam specimen. It is preferred that the beam specimens have a small preexisting notch to ensure mode I cracking in a three-point bending test. The other required material properties for the use of nondimensionalized graphs include Young's modulus and tensile strength. Since the three-point bending test can be easily carried out in the laboratory, the proposed method offers a practical, yet expedient, way of characterizing the nonlinear fracture properties of materials that follow the linear stress-separation behavior in the process zone.