The effects of thermal residual stresses and interfacial properties on the transverse behaviors of fiber composites with different microstructures

2017 ◽  
Vol 24 (1) ◽  
pp. 41-51 ◽  
Author(s):  
Xiaojun Zhu ◽  
Xuefeng Chen ◽  
Zhi Zhai ◽  
Zhibo Yang ◽  
Qiang Chen
Keyword(s):  
Residual Stresses ◽  
Cohesive Zone Model ◽  
Micromechanical Model ◽  
Interfacial Properties ◽  
Zone Model ◽  
Computational Accuracy ◽  
Fiber Model ◽  
Thermal Residual Stresses ◽  
Generalized Method Of Cells ◽  
Experimental Values

AbstractThis study presents a new micromechanical model to investigate the effects of thermal residual stresses and interfacial properties on the transverse behaviors of SiC/Ti composites with different microstructures. In this model, the fiber-matrix interface is modeled by the bilinear cohesive zone model. The interface model is introduced into the generalized method of cells, which has the advantage of computational accuracy and efficiency. At the same time, the generalized method of cells is extended to consider thermal residual stresses within the fiber and matrix phases. Thermal residual stresses are found to have a significant influence on the transverse behaviors of the composites. Compared with the perfect interface, the transverse behaviors of the composites with weak interface bonding are much lower. Moreover, with the increase of fiber fraction, the stiffness of the composites increases before debonding occurs while the saturation stress decreases. The predicted results using the circular fiber model and considering thermal residual stresses are more consistent with the experimental values compared with the results using the square or elliptical fiber model. When the stress concentration factor is considered and the interface is weakly bonding, the strength predictions are much better than the results using the perfect bonding.

scholarly journals Influence of Stress on Kinetics and Transformation Plasticity of Ferrite Transformation Based on Hysteresis Effects

Metals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 73 ◽  
Author(s):  
Wenhong Ding ◽  
Yazheng Liu ◽  
Jianxin Xie ◽  
Li Sun ◽  
Tianwu Liu
Keyword(s):  
Residual Stresses ◽  
Micromechanical Model ◽  
Transformation Plasticity ◽  
Cooling Process ◽  
Mechanical Stabilization ◽  
Continuous Cooling ◽  
Ferrite Transformation ◽  
External Stresses ◽  
Transformation Hysteresis ◽  
Experimental Values

Transformation plasticity and kinetics play an essential role in the prediction of residual stresses resulting from transformation. This paper is devoted to the investigation of the influence of stress on the kinetics and transformation plasticity of ferrite for H420LA steel. It has been shown that under small external stresses, lower than the yield stress of the weaker phase, the ferrite transformation is inhibited at the beginning of the transformation in the continuous cooling process and the mechanical stabilization of austenite is observed, due to transformation hysteresis effects. This phenomenon affects the metallurgical and mechanical behaviors of the transformation progress. However, most existing models ignore these effects, leading to deviations in the description of transformation plasticity during the transformation progress. Considering the hysteresis effects, the micromechanical model for kinetics and transformation plasticity is reexamined. A general formulation of austenite decomposition kinetics accounting for these effects is developed to better describe the phase transformation under a continuous cooling process. In addition, the influence of hysteresis effects on the evolution of transformation plasticity is analyzed. Consideration of the hysteresis effects decreases the discrepancy between the calculated and experimental values. This will allow better prediction of residual stresses in the thermomechanically controlled processes.

The Research of the Effective Moduli of Particle Reinforced Polymer Composites Based on Interface Debonding

2009 ◽  
Vol 413-414 ◽  
pp. 211-217
Author(s):  
Xin Long Chang ◽  
Bin Jian ◽  
Chang Ouyang
Keyword(s):  
Polymer Composites ◽  
Cohesive Zone Model ◽  
Volume Fraction ◽  
Micromechanical Model ◽  
Interface Debonding ◽  
Zone Model ◽  
Effective Moduli ◽  
Reinforced Polymer ◽  
The Matrix ◽  
Particulate Size

This paper is devoted to studying influences of matrix/particle interface debonding and particulate size in micromechanical predictions of the effective moduli of particulate reinforced polymer composites (PRPC). The PRPC is regarded as a three-phase composite that includes the matrix, particle and interphase. The formulation for the effective moduli of the interphase is derived by the cohesive zone model, and combined with the Mori-Tanaka method, the micromechanical model for the effective moduli of the PRPC is formulated with emphasis on the effects of the matrix/particle interface, particulate size and volume fraction. The numerical example shows that the interface debonding, the particulate size and volume fraction have significant influences on the effective moduli of PRPC. The effective moduli of the PRPC can be used to characterize its damage degree.

Implementing a Cohesive Zone Interface in a Diamond-Coated Tool for 2D Cutting Simulations

2012 ◽  
Author(s):  
Feng Qin ◽  
Ninggang Shen ◽  
Kevin Chou
Keyword(s):  
Residual Stresses ◽  
Mechanical Behavior ◽  
Cohesive Zone ◽  
Cohesive Zone Model ◽  
Chip Thickness ◽  
Zone Model ◽  
Cohesive Failure ◽  
Cutting Simulation ◽  
Coated Tool ◽  
Coating Delamination

Coating-substrate interface properties and deposition residual stresses may have significant effects on diamond-coated tool performance. However, it is still distant to understand how the interface mechanical behavior and deposition residual stress together influence the diamond-coated tool thermo-mechanical behavior during machining. In this study, a 2D cutting simulation incorporating deposition residual stresses and an interface cohesive zone model has been developed to demonstrate the feasibility of evaluating coating delamination of a diamond-coated tool during cutting. It has been shown that even the residual deposition stresses alone may result in crack initiations in the cohesive zone (i.e., the interface). In addition, the study further demonstrates that the feasibility of implementing cohesive zone interface in a diamond-coated tool in 2D cutting simulation. An example of cohesive failure occurred in the cutting simulation is shown. The result shows a large uncut chip thickness can cause cohesive delamination during cutting.

The failure mechanism of carbon fiber-reinforced composites under longitudinal compression considering the interface

2017 ◽  
Vol 24 (3) ◽  
pp. 429-437 ◽  
Author(s):  
Geng Han ◽  
Zhidong Guan ◽  
Xing Li ◽  
Ruipeng Ji ◽  
Shanyi Du
Keyword(s):  
Failure Mechanism ◽  
Failure Mode ◽  
Cohesive Zone Model ◽  
Progressive Failure ◽  
Micromechanical Model ◽  
Kink Band ◽  
Zone Model ◽  
Longitudinal Compression ◽  
Fiber Failure ◽  
Damage Initiation

AbstractIn this paper, a longitudinal compression experiment of composites was conducted and the macroscopic failure mode was obtained. Also, the microscopic failure morphologies of longitudinal compression and kink band were observed by using scanning electron microscopy. It can be seen that, under compression, fibers bend and form a kink band, which is the most typical failure mode. Then a micromechanical model of fiber random distribution based on the random collision algorithm, which can reveal the progressive failure mechanism of longitudinal compression considering the kink-band deformation, was established, with two dominant damage mechanisms – plastic deformation and ductile damage initiation of the polymer matrix and interfacial debonding included in the simulation by the extended Drucker-Prager model and cohesive zone model, respectively. Through numerical simulation, the loading and failure procedures were divided into three stages: elastic domain, softening domain and fiber failure domain. It can be concluded that the kink band was a result of fiber instability (micro-bulking), which is caused by the elastic bending of fibers. The fibers rotate and break into two places, forming a kink band. Then the fibers rotate further until the matrix between the fibers fails and the kink-band breaks and, hence, the composite loses its load-bearing capability.

The influence of fiber surface profile and roughness to fiber–matrix interfacial properties

2019 ◽  
Vol 54 (11) ◽  
pp. 1441-1452
Author(s):  
Ichsan Setya Putra ◽  
Bentang Arief Budiman ◽  
Poetro Lebdo Sambegoro ◽  
Sigit Puji Santosa ◽  
Andi Isra Mahyuddin ◽  
...  
Keyword(s):  
Composite Structures ◽  
Cohesive Zone Model ◽  
Surface Profile ◽  
Interfacial Strength ◽  
Fiber Surface ◽  
Interfacial Properties ◽  
Zone Model ◽  
The Matrix ◽  
Fiber Matrix ◽  
New Perspective

This work investigates the influence of fiber surface profile and roughness to fiber–matrix interfacial properties. A series of the push-out test is performed using specimens with different fiber surface profile and roughness. Numerical simulation is then carried out by employing a finite element method to fit the experimental data. The model contains an indenter which pushes in a single fiber from the matrix, while the cohesive zone model is applied to represent the interface resulting in force–displacement curves. Our results suggest that continuous cavities formed in graphite-based fiber may not be beneficial to interfacial properties since it can accelerate a debonding process along with the interface. In contrast, scattered cavities on the fiber surface create strong mechanical locking, which increases the interfacial strength. These results broaden the understanding of the surface profile, which would shed light on a new perspective in designing composite structures.

Finite Element Analysis of the Effect of Residual Stress on Mechanical Behavior of Welded Plates

2008 ◽  
Vol 580-582 ◽  
pp. 605-608
Author(s):  
Byeong Choon Goo ◽  
Seung Yong Yang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Crack ◽  
Residual Stresses ◽  
Crack Propagation ◽  
Mechanical Behavior ◽  
Fatigue Crack Propagation ◽  
Cohesive Zone Model ◽  
Zone Model ◽  
Element Analysis

Residual stresses play an important role in the mechanical behavior of steels and welded structures. To examine the effect of residual stresses on tensile behavior and fatigue, residual stresses in the specimens were generated by welding. Experimental stress-strain curves of the specimens with/without residual stresses were obtained and compared to simulated curves obtained by the finite element analysis. The two results are in a good agreement. Finally, to study the relaxation of the residual stresses during fatigue crack propagation, we carried out fatigue crack propagation analysis by a 3-D cohesive zone model. Initial welding residual stresses decrease as the number of cycles increases.

Cracking Simulation of Asphalt Mixtures Using a Finite Element Micromechanical Model

2012 ◽  
Vol 598 ◽  
pp. 477-483
Author(s):  
Jing Hui Liu
Keyword(s):  
Finite Element ◽  
Cohesive Zone Model ◽  
Model Simulation ◽  
Micromechanical Model ◽  
Asphalt Mixture ◽  
Heterogeneous Material ◽  
Tensile Tests ◽  
Asphalt Mixtures ◽  
Zone Model ◽  
Material Heterogeneity

Cracking in the surface layer of asphalt pavement has been shown to be a major source of distress in roadways. Asphalt mixture is typically a heterogeneous material composed of aggregates, binder and air voids. Previous cracking studies have not considered the material heterogeneity. Digital Image Processing techniques is a powerful tool to describe the microstructure of the material. A micromechanical cohesive zone model that introduces ductility at the crack tip has been used to simulate the cracking of asphalt mixtures. ABAQUS software is a convenient finite element method to conduct simulations of particular laboratory specimens such as Indirect Tensile Tests(IDT) considering the micromechanical model. Simulation results of the IDT compared favorably with experimental results. Even though this study presented a attempt of a numerical simulation of a simple IDT test, the theory and methods adopted by the study can be applied to the fatigue damage study under the complicated loading considering the material heterogeneity, and then would effectively allow researchers link the micro-scale damage observed on the local scale with the real pavements fail on the global scale.

Micromechanical Model of Interface between Fibre and Matrix of Metal Matrix Composite Reinforced with Continuous Fibre

2008 ◽  
Vol 59 ◽  
pp. 158-163 ◽  
Author(s):  
A. Ríos ◽  
A. Martín-Meizoso
Keyword(s):  
Finite Element Method ◽  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Cohesive Zone ◽  
Metal Matrix ◽  
Cohesive Zone Model ◽  
Micromechanical Model ◽  
Zone Model ◽  
Cohesive Elements ◽  
The Matrix

A micromechanical model is employed to investigate the influence of the interface between the fibre and the matrix of a metal matrix composite with long fibre, which is elaborated through finite element method. Also, transverse properties of composite are studied in the present work. The interface, between the fibre and the matrix, is studied employing cohesive elements. These elements employ a cohesive zone model, which follows a bilinear law.

Implementing a Cohesive Zone Interface in a Diamond-Coated Tool for 2D Cutting Simulations

2014 ◽  
Vol 1 (1) ◽  
pp. 31-47
Author(s):  
Feng Qin ◽  
Kevin Chou
Keyword(s):  
Residual Stresses ◽  
Mechanical Behavior ◽  
Cohesive Zone ◽  
Cohesive Zone Model ◽  
Chip Thickness ◽  
Zone Model ◽  
Cutting Simulation ◽  
Tool Performance ◽  
Coated Tool ◽  
Coating Delamination

The interface properties and deposition residual stresses may have significant effects on the diamond-coated tool performance. However, it is still not fully understood how the interface mechanical behavior and deposition residual stress together influence the thermo-mechanical behavior of a diamond-coated tool during machining. In this study, a two-dimensional (2D) cutting simulation incorporating both deposition residual stresses and an interface cohesive zone model has been developed to demonstrate the feasibility of evaluating coating delamination of a diamond-coated tool during cutting. It has been shown that even the residual deposition stresses alone may result in failure initiations in the cohesive zone (i.e., the interface). In addition, the study further demonstrates the implementation of a cohesive zone interface in a diamond-coated tool in 2D cutting simulation. An example of cohesive failures occurred during the cutting simulation is presented. The result further shows that a larger uncut chip thickness will result in cohesive delamination of the coating-substrate interface during cutting.

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