String-based cohesive zone model: implicit integration scheme and calibration method

摘要

The objective of this paper is to develop the implicit integration scheme and calibration method for a recently developed cohesive zone model (CZM), for improved predictive capabilities in interlaminar delamination. The concept of string-based CZM is briefly introduced. An associated implicit integration scheme, which can handle complex separation paths and mixed-mode fracture, is developed, and the implicit CZM is implemented in an implicit solver via a user subroutine, for structural analysis. The constant interface parameters are identified from a thermodynamic perspective, and a systemic method for model calibration is subsequently developed. The present CZM is validated by calibrating its constant parameters via a series of flexural tests. The integration scheme is found to produce improved convergence and accuracy. The calibration method is found to provide a reliable guide to model calibration. The present CZM can be modified to accommodate other types of debonding or fracture.