Experimental Study on the Caustics of Moving Cracks and Elliptical Curvature under Impact Loading

Abstract

A dynamic caustics test system was used, and different moving cracks were analysed to study the interaction between the crack growth rate, stress intensity factor, and curvature of the elliptical end of a moving crack under impact loading. Based on the linear elastic fracture mechanics theory, linearly fitting of the crack tip stress intensity factor and the elliptical curvature were employed to obtain the specific functional expressions. ABAQUS software was used to numerically simulate the moving crack fracture process passing through different elliptical curvatures. The crack tip stress intensity factor was calculated by the stress extrapolation method. The stress intensity factor obtained from the numerical calculation and the caustics test was consistent. The test and numerical simulation results showed that the direction of moving cracks entering and passing through the elliptical defects shows a certain regularity. As the ellipse curvature increased, the moving crack stress intensity factor passing through the ellipse gradually decreased, and the moving crack also passed easily through oval defects.

2D numerical modeling of crack propagation using SFEMD method of a LEHI material

“…The SIF was calculated from the J-integral, using the finite element method by (Toribio et al, 2021;Christer;Kjell, 2021) extended a work to include the area integral (J) by deriving it as a function of displacements only, to also obtain the alternative method of calculating (J) in peri-dynamics. Therefore, the stress intensity factor at crack tip were calculated by the stress extrapolation method (Luo et al, 2021) such as the stress intensity factor (KI, KII) and the integral of the contour (J). Among these studies we cite the work (Shuai et al, 2021) created a modified J-integral calculation method is adopted to solve the problem of evaluating crack propagation of shot-blasted structures.…”