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), Kd, were obtained. Experiments were conducted using a PSM-1/aluminum bimaterial system subjected to quasi-static loading to determine Kd 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 Kd 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.