A study on the impact failure mechanism of aluminum-PMMA interfacial crack

Energy release rate (J integral) and stress intensity factors of bimaterial specimens, under the dynamic loading condition were studied using both numerical and experimental methods. Low velocity impact test was performed with three point bending type of bimaterial specimens composed of aluminum and PMMA [Poly-Methyl Methacrylate]. Experimental results were analyzed by FEM and fracture parameters of interfacial crack were calculated by the programmed post-processor. Domain integral method and interaction energy method were used in the post-processor. Post-processor showed good performance in the decomposition of stress intensity factors with path independency. Phase angle of stress intensity factor varied with time. The relationship between energy release rate and phase angle at the onset of crack propagation showed unsymmetrical graph.