Analysis of resistance cracking process on the experiment of meso and macroscopic of quasi-brittle materials

摘要

Engineering materials such as cast iron and concrete are quasi-brittle materials, and there is a fracture process zone in front of opening crack and it exist micro and macro defect and energy dissipation. The damage development area is simplified into fictitious crack, and its action stress distribution and opening displacement or deformation are along the cohesive crack. In order to investigate the constitutive relation of cohesive crack opening displacement and its stress distribution in quasi brittle materials, cast iron and concrete were used to test their fracture process by electronic equipment and micro view experiment facility. Through the analytical method of applied mathematics and mechanics, the material deformation stress constitutive relations were gotten for the cohesive crack. The theoretical calculation and test results are basically in agreement with each other. From the fracture criterion of Double K and the mechanics model of cohesive crack, the bearing capacity of structure with crack was estimated in this present paper.