A Nodal-Based Lagrange Multiplier/Cohesive Zone Approach For Dynamic Interfacial Cracking Analysis Of Thin-Walled Laminated Composite Structures

Although the intrinsic cohesive zone models (CZMs) have become a popular approach for interfacial cracking analysis in laminated composite structures, they suffer from the so-called artificial compliance issue for the modelling of strong adhesion between laminate layers. The objective of this work is twofold: (1) to propose a novel nodal-based Lagrange multiplier/cohesive zone (LM/CZ) method to address such aforementioned non-physical numerical issue; (2) to focus the applications of interest on interfacial cracking of thin-walled laminated composites discretized with solid-shell elements. In sharp contrast to the penalty-based numerical treatment used in the intrinsic CZMs, our approach enforces the continuities across material interfaces via Lagrange multipliers (LMs) at finite element nodes before the onset of interfacial cracking. A smooth transition is guaranteed during the switch of interfacial constraints from LMs to cohesive forces at the time of crack onset. This approach employs a shifted traction-separation law to govern the gradual cohesive cracking process. Several numerical examples are performed to demonstrate the accuracy and capacity of the proposed approach.