Abstract
Image analysis with ultra-high-speed camera and dynamic numerical analysis are applied to the unstable crack growth of wing crack under the uniaxial compression. During the unstable growth, growing wing crack terminates and restarts their growth in some cases. The termination and restart behavior of the growing crack is discussed through the experiment and numerical analysis in this research.
First, images of rapid propagation of wing cracks under uniaxial compression are captured by the ultra-high-speed camera with the frame rate of 500k frames per second. Stress field around the moving crack tip is visualized by means of photo-elastic technique, and images of the resultant fringe patter are also captured by the camera.
Next, two dimensional dynamic numerical analysis is performed. PDS-FEM (Particle Discretization Scheme), which allows the discontinuity of the displacement in the continuous body, is combined with the central difference time integration scheme to simulate the unstable growth of the wing crack dynamically. The accuracy of the simulation is discussed through the comparison with the images which are captured by the high speed camera.
