The effect of cross-section shape on deformation, damage and failure of rock-like materials under uniaxial compression from both a macro and micro viewpoint

摘要

The mechanical properties of rock-like materials always attract the interest of many researchers. In this paper, we study the influence of specimen cross-section shape on uniaxial compressive strength as well as their deformation, damage and failure characteristics by uniaxial compression tests. The diameter and height of circular cross-section specimens are 50 and 100 mm, respectively, and the height and cross-sectional area of other specimens are equal to that of circular cross-sectional ones. Simulation and experimental results show that the cross-sectional shape has little effect on uniaxial compressive strength. Moreover, the effect on other mechanical properties is also very limited before the peak strength, such as stress-strain curve, rotation and motion of particles, contact damage and energy evolution of particles; however, it gradually becomes obvious after the peak strength. This is a very important feature, which affects the macroscopic form of failure of specimens and reflects the difference between failure surfaces. The shapes of failure surfaces obtained from numerical simulations are quite similar to the experimental results, which verify the reliability of numerical simulation results. Finally, the achievements can serve as a reference for related engineering issues.