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 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.

Estimating the Cohesive Zone Model Parameters of Carbon Nanotube–Polymer Interface for Machining Simulations

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Lingyun Jiang ◽  
Chandra Nath ◽  
Johnson Samuel ◽  
Shiv G. Kapoor
Keyword(s):  
Carbon Nanotube ◽  
Cohesive Zone ◽  
Cohesive Zone Model ◽  
Interfacial Strength ◽  
Weight Fraction ◽  
Model Parameters ◽  
Zone Model ◽  
Fe Model ◽  
Polymer Interface ◽  
Two Parameters

The failure mechanisms encountered during the machining of carbon nanotube (CNT) polymer composites are primarily governed by the strength of the CNT–polymer interface. Therefore, the interface should be explicitly modeled in microstructure-level machining simulations for these composites. One way of effectively capturing the behavior of this interface is by the use of a cohesive zone model (CZM) that is characterized by two parameters, viz., interfacial strength and interfacial fracture energy. The objective of this study is to estimate these two CZM parameters of the interface using an inverse iterative finite element (FE) approach. A microstructure-level 3D FE model for nanoindentation simulation has been developed where the composite microstructure is modeled using three distinct phases, viz., the CNT, the polymer, and the interface. The unknown CZM parameters of the interface are then determined by minimizing the root mean square (RMS) error between the simulated and the experimental nanoindentation load–displacement curves for a 2 wt. % CNT–polyvinyl alcohol (PVA) composite sample at room temperature and quasi-static strain state of up to 0.04 s−1, and then validated using the 1 wt. % and 4 wt. % CNT–PVA composites. The results indicate that for well-dispersed and aligned CNT–PVA composites, the CZM parameters of the interface are independent of the CNT loading in the weight fraction range of 1–4%.

Simulation and Analysis on Fiber Reinforced Rubber Matrix Sealing Composite Based on Cohesive Zone Model

2019 ◽  
Vol 953 ◽  
pp. 65-71
Author(s):  
Xiao Ming Yu ◽  
Bin Zhang ◽  
Jia Min Shen ◽  
Yue Li ◽  
Sai Sai Liu
Keyword(s):  
Elastic Modulus ◽  
Cohesive Zone ◽  
Cohesive Zone Model ◽  
Element Model ◽  
Interfacial Debonding ◽  
Interfacial Stress ◽  
Rubber Matrix ◽  
Zone Model ◽  
Fiber Reinforced ◽  
Pull Out

A finite element model on the single fiber pull-out test of short fiber reinforced rubber matrix sealing composites (SFRC) were established. The effects of the interphase properties on the interfacial stress distribution and initial debonding strain are investigated based on the cohesive zone model (CZM). The influences of interphase thicknesses and elastic modulus on the interfacial debonding behavior of SFRC are obtained. The results show that the interfacial initial debonding strain increases with the increasement of interphase thickness, and it decreases with the increasement of interphase elastic modulus. An interphase thickness of 0.4 μm and an interphase elastic modulus of about 750 MPa are optimal to restrain the initiation of the interfacial debonding.

Estimating the Cohesive Zone Model Parameters for Carbon Nanotube–Polymer Interface Using Inverse Finite Element Approach

2012 ◽  
Author(s):  
Lingyun Jiang ◽  
Chandra Nath ◽  
Johnson Samuel ◽  
Shiv G. Kapoor
Keyword(s):  
Finite Element ◽  
Carbon Nanotube ◽  
Fracture Energy ◽  
Cohesive Zone ◽  
Cohesive Zone Model ◽  
Interfacial Strength ◽  
Model Parameters ◽  
Zone Model ◽  
Displacement Curve ◽  
Polymer Interface

During machining of carbon nanotube (CNT)-polymer composites, the failure of the polymer elements occurs at the CNT-polymer interface. The interfacial behavior that can be represented by a cohesive zone model (CZM) is mainly influenced by two parameters, viz., interfacial strength and fracture energy. The objective of this study is to estimate these two specific CZM parameters using an inverse finite element (FE) simulation approach that works based on an iterative error minimization procedure. Nanoindentation tests have been conducted on a CNT-polyvinyl alcohol (PVA) composite sample containing 4 wt% multi-walled nanotubes (MWNTs). A 2D axisymmetric FE model of nanoindentation has been developed. This micro-structure based model considers the CNT, the PVA, and the cohesive zone of interface as three individual phases. The unknown interfacial parameters are determined by minimizing the error between the simulation load-displacement curve and the experimental results. The interfacial strength and the fracture energy at the CNT-PVA interface are estimated to be approximately 40 MPa and 16e−3 J/m2, respectively. This approach provides a convenient framework to understand the role of the CZM parameters at the interface between the CNT and polymer matrix.

Progressive Damage Analysis of Random Chopped Fiber Composite Using Finite Elements

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
Yi Pan ◽  
Assimina A. Pelegri
Keyword(s):  
Mechanical Properties ◽  
Cohesive Zone Model ◽  
Fiber Composite ◽  
Damage Model ◽  
Interfacial Debonding ◽  
Matrix Cracking ◽  
Uniaxial Tensile ◽  
Zone Model ◽  
Progressive Damage ◽  
Fiber Damage

The mechanical properties of random chopped fiber composites are analyzed using micromechanical principles. A progressive damage model is adopted to investigate the damage and failure of the material. A representative volume element is generated numerically based on microscopic observations that capture the complex mesostructure of the random chopped fiber composite specimens. Sequentially, the mechanical properties are obtained using a micromechanics approach, particularly, the homogenization method. The underlying hypothesis insinuates that damage mechanisms such as matrix cracking, fiber damage, and interfacial debonding are responsible for the damaged behavior of the composite. Matrix cracking and fiber damage are modeled by progressive degradation of their respective stiffnesses. The interfacial debonding is modeled with a cohesive zone model. The prediction of uniaxial tensile response is compared with experimental data.

scholarly journals Ultrasonic Deicing Efficiency Prediction and Validation for a Flat Deicing System

2020 ◽  
Vol 10 (19) ◽  
pp. 6640
Author(s):  
Zhonghua Shi ◽  
Zhenhang Kang ◽  
Qiang Xie ◽  
Yuan Tian ◽  
Yueqing Zhao ◽  
...  
Keyword(s):  
Lead Zirconate Titanate ◽  
Cohesive Zone ◽  
Cohesive Zone Model ◽  
Lead Zirconate ◽  
Efficiency Factor ◽  
Zone Model ◽  
Shear Stresses ◽  
Stress Distributions ◽  
Total Energy Density ◽  
Average Shear

An effective deicing system is needed to be designed to conveniently remove ice from the surfaces of structures. In this paper, an ultrasonic deicing system for different configurations was estimated and verified based on finite element simulations. The research focused on deicing efficiency factor (DEF) discussions, prediction, and validations. Firstly, seven different configurations of Lead zirconate titanate (PZT) disk actuators with the same volume but different radius and thickness were adopted to conduct harmonic analysis. The effects of PZT shape on shear stresses and optimal frequencies were obtained. Simultaneously, the average shear stresses at the ice/substrate interface and total energy density needed for deicing were calculated. Then, a coefficient named deicing efficiency factor (DEF) was proposed to estimate deicing efficiency. Based on these results, the optimized configuration and deicing frequency are given. Furthermore, four different icing cases for the optimize configuration were studied to further verify the rationality of DEF. The effects of shear stress distributions on deicing efficiency were also analyzed. At same time, a cohesive zone model (CZM) was introduced to describe interface behavior of the plate and ice layer. Standard-explicit co-simulation was utilized to model the wave propagation and ice layer delamination process. Finally, the deicing experiments were carried out to validate the feasibility and correctness of the deicing system.

Sign in / Sign up

Export Citation Format

Share Document