Experimental investigation of the stress field around the crack tip in a polymer material under dynamic loading

Abstract

A dynamic photoelasticity-caustic experimental system is established to quantitatively visualize and characterize the distribution of an entire stress field. The evolution of both the singular stress and far-field stress around the crack tip can be precisely determined using the proposed multiparameter solution. Moreover, the accuracy of the proposed stress inverse calculation method increased with an increasing number of parameters. The reconstructed isochromatic fringes based on 12-parameter solutions agreed well with the results obtained by the photoelasticity technique. Moreover, the influence of the parameters on the crack propagation behaviors was comprehensively investigated. In addition, the numerical results showed that the 12-parameter solution was sufficient for modeling the stress field around the crack tip, which enlarged the estimation region by at least 50 times compared with that of the traditional three-parameter (KId, KIId, and T-stress) solution.