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.

中文翻译：

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基于字符串的内聚区模型：隐式积分方案和标定方法

本文的目的是为最近开发的内聚区模型 (CZM) 开发隐式积分方案和校准方法，以提高层间分层的预测能力。简要介绍了基于字符串的 CZM 的概念。开发了一种相关的隐式积分方案，可以处理复杂的分离路径和混合模式断裂，隐式 CZM 通过用户子程序在隐式求解器中实现，用于结构分析。从热力学角度确定了恒定的界面参数，随后开发了模型校准的系统方法。目前的 CZM 是通过一系列弯曲测试校准其常数参数来验证的。发现集成方案产生改进的收敛性和准确性。发现校准方法为模型校准提供了可靠的指导。目前的 CZM 可以修改以适应其他类型的脱粘或断裂。