Simulation of bridging mechanisms in complex laminates using a hybrid PF-CZM method

Abstract

Delamination and cracking of matrix/fiber is a common failure phenomena reported in fiber reinforced composite materials. As complex stress states develop in laminated structures, they are prone to develop fracture phenomena. Therefore, designs with large damage tolerance are currently implemented in most of the industrial sectors. This can be achieved by designing such materials with superior fracture resistance, which requires a comprehensive understanding of failure mechanisms. Cohesive Zone Models (CZM) are a popular technique to study debonding and decohesion in composite structures. Furthermore, due to the accurate simulation of complex crack paths including crack branching, the Phase Field (PF) approach has gained notable relevance in fracture studies, including the interplay between debonding and crack propagation in the matrix. In order to get a further insight into these intricate scenarios, involving bridging mechanisms in intralayer and interlayer, crack simulation coupling the phase field approach and the cohesive zone model is herein exploited for identifying crack migration through material layers. The crack paths and the related force–displacement curves of 2D multilayered material models of complex laminates are predicted and compared.

Keywords:

• Complex laminates
• bridging mechanisms
• delamination– migration
• cohesive zone model
• phase-field model

Acknowledgments

Budarapu thankfully acknowledges the financial support from IIT Bhubaneswar through the seed project SP-097, titled” Multiphysics Analysis of Cracked Photovoltaic Solar cells”. Support from the Italian Ministry of Education, University and Research to the Project of Relevant National Interest 2017 (PRIN)” XFAST-SIMS: Extra fast and accurate simulation of complex structural systems” (MUR grant agreement 20173C478N) is gratefully acknowledged by Paggi. J. Reinoso is grateful to the Consejería de Economía y Conocimiento of the Junta de Andalucía (Spain) for financial support under the contract US-1265577-Programa Operativo FEDER Andalucía 2014-2020, Spanish Ministerio de Ciencia, Innovación y Universidades the under the grant PID2019-109723GB-I00 and Consejería de Economía y Conocimiento of the Junta de Andalucía (Spain) under the grant P2-00595.

Notes

1 In simulations, the parameters used model the interfaces are derived at constant initial peak stress of 2 GPa. The corresponding parameters for a tough interface are: ${\sigma }_{\mathrm{c},0},{\tau }_{\mathrm{c},0}$ $=$ 2 GPa and $k_0,$ the initial stiffness is 0.8 MPa/mm with a critical normal crack opening distance of 0.0025 mm. Similarly the parameters for the brittle interface are: ${\sigma }_{\mathrm{c},0},{\tau }_{\mathrm{c},0}$ $=$ 2 GPa and the initial stiffness of interface is 80 MPa/mm with a critical normal crack opening distance of 0.000025 mm.