A molecular dynamics based cohesive zone model for interface failure under monotonic tension of 3D four direction SiCf/SiC composites

2021 ◽  
pp. 114397
Author(s):  
Rongqiao Wang ◽  
Jiangbo Han ◽  
Jianxing Mao ◽  
Dianyin Hu ◽  
Xi Liu ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Cohesive Zone ◽  
Cohesive Zone Model ◽  
Zone Model ◽  
Interface Failure ◽  
Sic Composites

Molecular Dynamics Simulation Based Cohesive Zone Representation of Intergranular Fracture Processes in Bicrystalline Graphene

2020 ◽  
Author(s):  
MD Imrul Reza Shishir ◽  
Alireza Tabarraei
Keyword(s):  
Molecular Dynamics ◽  
Grain Boundaries ◽  
Cohesive Zone ◽  
Cohesive Zone Model ◽  
Dynamics Simulation ◽  
Zone Model ◽  
Zone Method ◽  
Simulation Based ◽  
Dynamics Simulations ◽  
Fracture Processes

Abstract The fracture properties of various grain boundaries in graphene are investigated using the cohesive zone method (CZM). Molecular dynamics simulations are conducted using REBO2+S potential in order to develop a cohesive zone model for graphene grain boundaries using a double cantilever bicrystalline graphene sheet. The cohesive zone model is used to investigate the traction–separation law to understand the separation-work and strength of grain boundaries.

Crystal orientation dependence of crack growth and stress evolution in single crystal nickel: a molecular dynamics simulation-based cohesive zone model

RSC Advances ◽  
2015 ◽  
Vol 5 (81) ◽  
pp. 65942-65948 ◽  
Author(s):  
Yuan Qi ◽  
Wen-Ping Wu ◽  
Yun-Bing Chen ◽  
Ming-Xiang Chen
Keyword(s):  
Molecular Dynamics ◽  
Cohesive Zone ◽  
Crystal Orientation ◽  
Cohesive Zone Model ◽  
Orientation Dependence ◽  
Dynamics Simulation ◽  
Zone Model ◽  
Stress Evolution ◽  
Slip Bands ◽  
Simulation Based

Void forms in the sample with (100) orientation; brittle fracture in the sample with (110) orientation; blunting and slip bands occurs in the sample with (111) orientation.

Multiscale Model to Study the Effect of Interfaces in Carbon Nanotube-Based Composites

2005 ◽  
Vol 127 (2) ◽  
pp. 222-232 ◽  
Author(s):  
S. Namilae ◽  
N. Chandra
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Finite Element ◽  
Cohesive Zone ◽  
Cohesive Zone Model ◽  
Interfacial Region ◽  
Model Parameters ◽  
Zone Model ◽  
Pullout Tests ◽  
Nanoscale Interfaces

In order to fully harness the outstanding mechanical properties of carbon nanotubes (CNT) as fiber reinforcements, it is essential to understand the nature of load transfer in the fiber matrix interfacial region of CNT-based composites. With controlled experimentation on nanoscale interfaces far off, molecular dynamics (MD) is evolving as the primary method to model these systems and processes. While MD is capable of simulating atomistic behavior in a deterministic manner, the extremely small length and time scales modeled by MD necessitate multiscale approaches. To study the atomic scale interface effects on composite behavior, we herein develop a hierarchical multiscale methodology linking molecular dynamics and the finite element method through atomically informed cohesive zone model parameters to represent interfaces. Motivated by the successful application of pullout tests in conventional composites, we simulate fiber pullout tests of carbon nanotubes in a given matrix using MD. The results of the pullout simulations are then used to evaluate cohesive zone model parameters. These cohesive zone models (CZM) are then used in a finite element setting to study the macroscopic mechanical response of the composites. Thus, the method suggested explicitly accounts for the behavior of nanoscale interfaces existing between the matrix and CNT. The developed methodology is used to study the effect of interface strength on stiffness of the CNT-based composite.

scholarly journals Molecular Dynamics-Based Cohesive Zone Model for Mg/Mg17Al12 Interface

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 836
Author(s):  
Xiao Ru Zhuo ◽  
Aibin Ma
Keyword(s):  
Molecular Dynamics ◽  
Cohesive Zone ◽  
Fracture Process ◽  
Cohesive Zone Model ◽  
Zone Model ◽  
Separation Curve ◽  
Normal Traction ◽  
Cubic Polynomial ◽  
Simulation Results ◽  
Dynamics Simulations

The fracture of the Mg/Mg17Al12 interface was investigated by molecular dynamics simulations. The interface crack extends in a brittle manner without noticeable plasticity. The distributions of normal stress and separation along the interface were examined to render a quantitative picture of the fracture process. A normal traction–separation curve was extracted from simulation and compared with three cohesive zone models, i.e., cubic polynomial cohesive zone model, exponential cohesive zone model, and bilinear cohesive zone model. The exponential cohesive zone model exhibits the best agreement with simulation results, followed by the bilinear cohesive zone model.

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.

scholarly journals An Improved Cohesive Zone Model for Interface Mixed-Mode Fractures of Railway Slab Tracks

2021 ◽  
Vol 11 (1) ◽  
pp. 456
Author(s):  
Yanglong Zhong ◽  
Liang Gao ◽  
Xiaopei Cai ◽  
Bolun An ◽  
Zhihan Zhang ◽  
...  
Keyword(s):  
Interface Crack ◽  
Cohesive Zone ◽  
Mixed Mode ◽  
Cohesive Zone Model ◽  
Complex Loading ◽  
Bending Test ◽  
Mixed Mode Fracture ◽  
Zone Model ◽  
Slab Track ◽  
Interfacial Cracks

The interface crack of a slab track is a fracture of mixed-mode that experiences a complex loading–unloading–reloading process. A reasonable simulation of the interaction between the layers of slab tracks is the key to studying the interface crack. However, the existing models of interface disease of slab track have problems, such as the stress oscillation of the crack tip and self-repairing, which do not simulate the mixed mode of interface cracks accurately. Aiming at these shortcomings, we propose an improved cohesive zone model combined with an unloading/reloading relationship based on the original Park–Paulino–Roesler (PPR) model in this paper. It is shown that the improved model guaranteed the consistency of the cohesive constitutive model and described the mixed-mode fracture better. This conclusion is based on the assessment of work-of-separation and the simulation of the mixed-mode bending test. Through the test of loading, unloading, and reloading, we observed that the improved unloading/reloading relationship effectively eliminated the issue of self-repairing and preserved all essential features. The proposed model provides a tool for the study of interface cracking mechanism of ballastless tracks and theoretical guidance for the monitoring, maintenance, and repair of layer defects, such as interfacial cracks and slab arches.

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