Using strain gages to investigate subsonic dynamic interfacial fracture in an isotropic-isotropic bimaterial

In this experimental study, strain fields were used to investigate the behavior of subsonic interfacial crack propagation in a bimaterial system. Strain field equations were derived from the available stress field equations and critically evaluated in a parametric study. The feasibility of using strain gages was then demonstrated in model experiments in which values of the dynamic complex stress intensity factor (CSIF), , were obtained. Experiments were conducted using a PSM-1/aluminum bimaterial system subjected to quasi-static loading to determine and mixity φ. The first-order analysis of the strain gage data, which was conducted using two-gage and three-gage methods, resulted in values for CSIF, which compared very well to values of obtained from higher-order photoelastic analysis. Finally, a design curve was prepared to facilitate the analysis of dynamic interfacial crack propagation problems using strain gage techniques.