Experimental and numerical research of the behavior of 3D internal cracks under uniaxial compression using 3D-ILC technology

Abstract

Uniaxial compression tests are one of the classic tests of solid mechanics. However, there remain some unsolved problems involving the test methods and numerical simulation. In the present study, in view of the difficulties in the manufacture of real internal cracks, glass, a classical material whose brittleness is quite close to that of natural rock material, is selected to generate pure closed internal cracks using 3D Internal Laser-Engraved Crack (3D-ILC) technology. Through the uniaxial compression test, we observe that the failure of specimens originates from the pre-existing internal crack. First, wing cracks are generated around it, which then propagate. As the load reaches the maximum bearing capacity, the later tensile crack eventually leads to the failure of the specimen. This test method can be used to observe and study the crack propagation process, failure law, failure mode and characteristic load of brittle materials. In the numerical analysis, adaptive grid method is used for grid division and update. The distribution of KI, KII, and KIII at the crack tip is obtained by M-Integral, and the crack propagation is simulated in combination with the maximum tensile stress (MTS) criterion. In terms of numerical simulation, the mode I/II/III propagation simulation of 3D internal crack is successfully realized, which is of great significance. At present, the research of 3D crack propagation and internal crack propagation has encountered bottlenecks in theory, experiment and numerical simulation. It is hoped that the experimental and numerical simulation methods in this paper can provide some reference.