An analytical and computational study on energy dissipation along fracture process zone in concrete

Abstract

The influence of the fracture process zone (FPZ) on the fracture properties is one of thernhottest topics in the field of fracture mechanics for cementitious materials. Within the FPZ in front of arntraction free crack, cohesive forces are distributed in accordance with the softening stress-separationrnconstitutive relation of the material. Therefore, further crack propagation necessitates energy dissipation,rnwhich is the work done by the cohesive forces. In this paper gf, the local fracture energy characterizingrnthe energy consumption due to the cohesive forces, is discussed. The computational expression of gf inrnthe FPZ can be obtained for any stage during the material fracture process regarding the variation of FPZ,rnwhether in terms of its length or width. Gfa, the average energy consumption along the crack extensionrnregion, has also been computed and discussed in this paper. The experimental results obtained from thernwedge splitting tests on specimens with different initial notch ratios are employed to investigate thernproperty of the local fracture energy gf and the average value Gfa over the crack extension length. Thesernresults can be used to indicate the influence of the FPZ. Additionally, changes in the length of the FPZrnduring the fracture process are also studied.rn