Rate-Dependent Cohesive Models for Dynamic Mode I Interfacial Propagation and Failure of Unidirectional Composite Laminates

Chenxu Zhang,Chao Zhang,Huifang Liu,Junchao Cao

doi:10.3390/coatings11020191

Chenxu Zhang, Chao Zhang + Show 2 more

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https://doi.org/10.3390/coatings11020191

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Journal: Coatings	Publication Date: Feb 7, 2021
Citations: 5	License type: CC BY 4.0

Affiliation: Northwestern Polytechnical University

Abstract

With the increasing application of composite materials in anti-impact structure, the development of reliable rate-dependent interlaminar constitutive model becomes necessary. This study aims to assess and evaluate the applicability of three types of rate-dependent cohesive models (logarithmic, exponential and power) in numerical delamination simulation, through comparison with dynamic test results of double cantilever beam (DCB) specimens made from T700/MTM28-1 composite laminate. Crack propagation length history profiles are extracted to calibrate the numerical models. Crack propagation contours and fracture toughness data are predicted, extracted and compared to investigate the difference of the three different rate-dependent cohesive models. The variation of cohesive zone length and force profiles with the implemented models is also investigated. The results suggest that the crack propagation length can be better predicted by logarithmic and power models. Although crack propagation length profiles are well predicted, the numerical calculated dynamic fracture toughness tends to be higher than that of experimental measured results. The three models also show differences in the prediction of maximum loading forces. The results of this work provide useful guidance for the development of more efficient cohesive models and more reliable interface failure simulation of impact problems.

Highlights

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The concept of cohesive zone was first proposed by Dugdale [7] and Barenblatt [8], in the study of crack-tip yielding and fracture of brittle materials
Initial studies of cohesive model were mainly on the crack propagation in brittle materials [9,10], which was gradually applied to the fracture simulation of other materials and structures, including interface failure of adhesively bonded joints [11] and delamination in composite laminates [12]

Summary

Introduction

Delamination is one of the main damage modes of composite structures subjected to impact loads, which will result in significant stiffness degradation of the structure [1,2,3,4]. For the simulation of delamination of composite materials, the cohesive model is the most widely used method [6]. The concept of cohesive zone was first proposed by Dugdale [7] and Barenblatt [8], in the study of crack-tip yielding and fracture of brittle materials. Initial studies of cohesive model were mainly on the crack propagation in brittle materials [9,10], which was gradually applied to the fracture simulation of other materials and structures, including interface failure of adhesively bonded joints [11] and delamination in composite laminates [12]

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