Revisiting the Problem of Debond Initiation at Fibre-Matrix Interface under Transversal Biaxial Loads - A Comparison of Several Non-Classical Fracture Mechanics Approaches

2016 ◽  
Vol 713 ◽  
pp. 232-235 ◽  
Author(s):  
L. Távara ◽  
I.G. García ◽  
Roman Vodička ◽  
C.G. Panagiotopoulos ◽  
Vladislav Mantič
Keyword(s):  
Fracture Mechanics ◽  
Cohesive Zone Model ◽  
Failure Criteria ◽  
Transverse Load ◽  
Zone Model ◽  
Interface Model ◽  
Matrix Interface ◽  
Linear Elastic ◽  
Energetic Approach ◽  
Fibre Matrix

Understanding matrix failure in LFRP composites is one of the main challenges when developing failure criteria for these materials. This work aims to study the influence of the secondary transverse load on the crack initiation at micro-scale. Four non-classical approaches of fracture mechanics are used to model the onset of fibre-matrix interface debonds: Linear Elastic Brittle Interface Model (LEBIM), an Energetic Approach for the Linear Elastic Brittle Interface Model (EA-LEBIM), an Energetic Approach for the bilinear Cohesive Zone Model (EA-CZM) and the Coupled Criterion of the Finite Fracture Mechanics (CC-FFM). Results obtained by these approaches predict that, for brittle fibre-matrix configurations, a secondary transverse compression reduces the critical value of the main transverse tension leading to the debond onset. This fact is not taken into account by the currently used failure criteria

Investigation on Interfacial Bonding Strength of Anisotropic Conducive Adhesive with a New Cohesive Zone Model

2010 ◽  
Vol 654-656 ◽  
pp. 1928-1931
Author(s):  
Jun Zhang ◽  
Yong Cheng Lin ◽  
Xin Li Wei ◽  
Liu Gang Huang
Keyword(s):  
Bonding Strength ◽  
Cohesive Zone ◽  
Thermal Cycle ◽  
Cohesive Zone Model ◽  
Zone Model ◽  
Interface Model ◽  
Damage Factor ◽  
Adhesive Film ◽  
User Subroutine ◽  
Interfacial Bonding Strength

A modified cohesive zone interface model with a damage factor was proposed to describe the effects of the thermal cycle and humidity aging on the strengths of adhesive joints. The damage factor can not only change the cohesive zone bonding strength but also affect the energies of separation. The modified cohesive zone interfacial model, as a user subroutine, is developed and implemented in ABAQUS to simulate the 90° peeling process of the specimens, which were bonded by anisotropic conducive adhesive film (ACF) and subjected to the cycle and humidity aging tests. The numerical simulated results well agree with experimental results, which confirmed the validity of the new model.

scholarly journals Crash Analysis of Aluminum/CFRP Hybrid Adhesive Joint Parts Using Adhesive Modeling Technique Based on the Fracture Mechanics

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3364
Author(s):  
Young Cheol Kim ◽  
Soon Ho Yoon ◽  
Geunsu Joo ◽  
Hong-Kyu Jang ◽  
Ji-Hoon Kim ◽  
...  
Keyword(s):  
Fracture Mechanics ◽  
Composite Laminates ◽  
Cohesive Zone Model ◽  
Failure Behavior ◽  
Zone Model ◽  
Displacement Curve ◽  
Adhesive Failure ◽  
Aluminum Composite ◽  
Explicit Finite Element ◽  
Modeling Techniques

This study describes the numerical simulation results of aluminum/carbon-fiber-reinforced plastic (CFRP) hybrid joint parts using the explicit finite-element solver LS-DYNA, with a focus on capturing the failure behavior of composite laminates as well as the adhesive capacity of the aluminum–composite interface. In this study, two types of adhesive modeling techniques were investigated: a tiebreak contact condition and a cohesive zone model. Adhesive modeling techniques have been adopted as a widely commercialized model of structural adhesives to simulate adhesive failure based on fracture mechanics. CFRP was studied with numerical simulations utilizing LS-DYNA MAT54 to analyze the crash capability of aluminum/CFRP. To evaluate the simulation model, the results were compared with the force–displacement curve from numerical analysis and experimental results. A parametric study was conducted to evaluate the effect of different fracture toughness values used by designers to predict crash capability and adhesive failure of aluminum/CFRP parts.

scholarly journals A parametric study of crack propagation in paintings caused by temperature and relative humidity cycles based on irreversible cohesive zone model

2020 ◽  
Author(s):  
Mohammad Yaghoub Abdollahzadeh Jamalabadi
Keyword(s):  
Relative Humidity ◽  
Crack Initiation ◽  
Cohesive Zone ◽  
Cohesive Zone Model ◽  
Initial Crack ◽  
Zone Model ◽  
Initiation Time ◽  
One Dimensional ◽  
Linear Elastic ◽  
Effects Of Temperature

Abstract The current paper aims to use an irreversible cohesive zone model to investigate the effects of temperature and relative humidity cycles on multilayer thin-film paintings crack pattern. The homogenous one-dimensional paint layers composed of alkyd and acrylic gesso over a canvas foundation (support) with known constant thicknesses are considered as the mechanical model of painting. Experimental data used for mathematical modeling of canvas as a linear elastic material and paint as a viscoelastic material with the Prony series. Fatigue damage parameters such as crack initiation time and maximum loads are calculated by an irreversible cohesive zone model used to control the interface separation. With the increase of the painting thickness and/or the initial crack length, the value of the maximum force increases. Moreover, by increasing the relative humidity (RH) and the temperature difference at loading by one cycle per day, the values of initiation time of delamination decrease. It is shown that the thickness of painting layers is the most important parameter in crack initiation times and crack growth rate in historical paintings in museums and conservation settings.

Interfacial Debonding and Stress Field Analysis on a Single Fiber Composite Using FEM

2008 ◽  
Author(s):  
Yi Pan ◽  
Assimina A. Pelegri
Keyword(s):  
Stress Field ◽  
Cohesive Zone ◽  
Cohesive Zone Model ◽  
Fiber Composite ◽  
Interfacial Strength ◽  
Interfacial Debonding ◽  
Field Analysis ◽  
Zone Model ◽  
Linear Elastic ◽  
Bonded Composite

Fiber debonding in a bundled fiber reinforced polymer composite is investigated by using finite element method and cohesive zone model. Fiber and matrix are modeled as isotropic and linear elastic materials. Fiber/matrix interface is represented by a cohesive zone model governed by the traction-separation law. Effects of interfacial strength on interfacial debonding and stress field in the bundled fiber composite are examined. The stress field of the debonding composite is compared to that of perfectly bonded composite.

scholarly journals Size effect in particle debonding: Comparisons between finite fracture mechanics and cohesive zone model

2018 ◽  
Vol 53 (14) ◽  
pp. 1941-1954 ◽  
Author(s):  
Timothée Gentieu ◽  
Julien Jumel ◽  
Anita Catapano ◽  
James Broughton
Keyword(s):  
Fracture Mechanics ◽  
Critical Load ◽  
Cohesive Zone ◽  
Cohesive Zone Model ◽  
Interface Strength ◽  
Particle Radius ◽  
Zone Model ◽  
Finite Fracture Mechanics ◽  
Particle Debonding ◽  
The Relationship

The present study aims at describing the debonding phenomenon of a particle embedded in an elastic matrix. Two types of fracture mechanics approaches are developed and compared in this context. The phenomenon is analytically described using a finite fracture mechanics approach, while numerical simulations are performed using a cohesive zone model to describe the decohesion process. Both methods rely on two mechanical parameters: the interface strength, σmax and the fracture energy, Gc, of the interface. Both modelling approaches produce results that show larger particles tend to debond before smaller ones although noticeable differences are observed, especially concerning the relationship between the critical load and the particle radius: in the framework of the FFM, the critical load is inversely proportional to the square root of the particle radius, while when using CZM, the critical load is inversely proportional to the particle radius.

Cohesive Zone Model and GTN Model Collation for Ductile Crack Growth

2007 ◽  
Vol 567-568 ◽  
pp. 145-148
Author(s):  
Vladislav Kozák ◽  
Ivo Dlouhý ◽  
Zdeněk Chlup
Keyword(s):  
Fracture Mechanics ◽  
Crack Propagation ◽  
Cohesive Zone ◽  
Cohesive Zone Model ◽  
Zone Model ◽  
Interface Elements ◽  
Ductile Crack Growth ◽  
Propagation Analysis ◽  
Wide Range ◽  
Finite Element Package

The micromechanical modelling encounters a problem that is different from basic assumptions of continuum mechanics. The material is not uniform on the microscale level and the material within an element has its own complex microstructure. Therefore the concept of a representative volume element (RVE) has been introduced. The general advantage, compared to conventional fracture mechanics, is that, in principle, the parameters of the respective models depend only on the material and not on the geometry. These concepts guarantee transferability from specimen to components over a wide range of dimensions and geometries. The prediction of crack propagation through interface elements based on the fracture mechanics approach (damage) and cohesive zone model is presented. The cohesive model for crack propagation analysis is incorporated into finite element package by interface elements which separations are controlled by the traction-separation law.

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