Experimental evaluation of cohesive zone model parameters for coated fabrics using digital image correlation technique

This work proposes an experimental evaluation based on digital image correlation (DIC) technology to obtain the cohesive zone model (CZM) parameters for coated fabrics. A calculation method for fracture energy was proposed based on the J-integral theory, and crack tip opening displacement (CTOD) was obtained through virtual extensometers. For specimens with single-edge crack (SEC) and center crack (CC), a bilinear traction-separation law was established to clarify the influence of crack configuration on the CZM parameters. The accuracy of the experimentally measured CZM parameters can be validated through an inversion approach integrating Isight and Abaqus. The results indicate that the relative errors of the maximum cohesive traction and the corresponding cohesive separation displacement between the two specimen types are both less than 2%. In contrast, the crack configuration has a significant impact on the fracture energy and the critical separation displacement. Specifically, the CC specimens demonstrate more sufficient energy dissipation due to more uniform stress distribution, with fracture energy reaching 45.69 kJ/m² and critical separation displacement measuring 1.006 mm. The verification revealed that the relative error between measured and inversion parameters was less than 5%, and the simulation curves accurately reproduced the fracture mechanical characteristics of the coated fabrics.