Modeling Damage Evolution in a Hybrid Ceramic Matrix Composite Under Static Tensile Load

1997 ◽  
Vol 119 (4) ◽  
pp. 401-407 ◽  
Author(s):  
N. Bonora ◽  
G. Newaz
Keyword(s):  
Tensile Stress ◽  
Damage Evolution ◽  
Failure Modes ◽  
Strain Response ◽  
Load Drop ◽  
Stress Strain ◽  
Matrix Cracks ◽  
The Matrix ◽  
Constitutive Response ◽  
Hybrid Ceramic

In this investigation, damage evolution in a unidirectional hybrid ceramic composite made from Nicalon and SiC fibers in a Lithium Aluminosilicate (LAS) glass matrix was studied. The static stress-strain response of the composite exhibited a linear response followed by load drop in a progressive manner. Careful experiments were conducted stopping the tests at various strain levels and using replication technique, scanning and optical microscopy to monitor the evolution of damage in these composites. It was observed that the constituents of the composite failed in a sequential manner at increasing strain levels. The matrix cracks were followed by SiC fiber failures near ultimate tensile stress. After that, the load drop was associated with progressive failure of the Nicalon fibers. Identification of these failure modes were critical to the development of a concentric cylinder model representing all three constituent phases to predict the constitutive response of the CMC computationally. The strain-to-failure of the matrix and fibers were used to progressively fail the constituents in the model and the overall experimental constitutive response of the CMC was recovered. A strain based analytical representation was developed relating stiffness loss to applied strain. Based on this formulation, damage evolution and its consequence on tensile stress-strain response was predicted for room temperature behavior of hybrid CMCs. The contribution of the current work is that the proposed strain-damage phenomenological model can capture the damage evolution and the corresponding material response for continuous fiber-reinforced CMCs. The modeling approach shows much promise for the complex damage processes observed in hybrid CMCs.

scholarly journals Stress–strain relationship model of glulam bamboo under axial loading

2020 ◽  
Vol 29 ◽  
pp. 2633366X2095872
Author(s):  
Yang Wei ◽  
Mengqian Zhou ◽  
Kunpeng Zhao ◽  
Kang Zhao ◽  
Guofen Li
Keyword(s):  
Tensile Stress ◽  
Compressive Stress ◽  
Failure Modes ◽  
Axial Loading ◽  
Tensile Failure ◽  
Stress Strain ◽  
Laminated Bamboo ◽  
Bamboo Scrimber ◽  
Strain Relationship ◽  
Strain Model

Glulam bamboo has been preliminarily explored for use as a structural building material, and its stress–strain model under axial loading has a fundamental role in the analysis of bamboo components. To study the tension and compression behaviour of glulam bamboo, the bamboo scrimber and laminated bamboo as two kinds of typical glulam bamboo materials were tested under axial loading. Their mechanical behaviour and failure modes were investigated. The results showed that the bamboo scrimber and laminated bamboo have similar failure modes. For tensile failure, bamboo fibres were ruptured with sawtooth failure surfaces shown as brittle failure; for compression failure, the two modes of compression are buckling and compression shear failure. The stress–strain relationship curves of the bamboo scrimber and laminated bamboo are also similar. The tensile stress–strain curves showed a linear relationship, and the compressive stress–strain curves can be divided into three stages: elastic, elastoplastic and post-yield. Based on the test results, the stress–strain model was proposed for glulam bamboo, in which a linear equation was used to describe the tensile stress–strain relationship and the Richard–Abbott model was employed to model the compressive stress–strain relationship. A comparison with the experimental results shows that the predicted results are in good agreement with the experimental curves.

scholarly journals Uniaxial Tensile Stress-Strain Response on the 3D Angle Interlock Woven Fabric Composite

2019 ◽  
Vol 7 (4.14) ◽  
pp. 430
Author(s):  
F. M.Z. Nasrun ◽  
M. F. Yahya ◽  
M. R. Ahmad ◽  
S. A. Ghani
Keyword(s):  
Tensile Stress ◽  
The Other ◽  
Woven Fabric ◽  
Uniaxial Tensile ◽  
Strain Response ◽  
Woven Composite ◽  
Stress Strain ◽  
Fabric Composite ◽  
Uniaxial Tensile Stress ◽  
Set Up

An experimental study have been performed to investigate the uniaxial tensile stress-strain response on the 3D angle interlock (3DAI) woven fabric composite. The tensile analysis were examined based on different woven fabric set-up parameter of draw-in plan ; pointed (DRW 1), broken (DRW 2), broken mirror (DRW 3), and straight (DRW 4). Meanwhile, the woven fabric composite were produced based on 22 and 25 pick.cm-1 of weft densities. The outcomes produced shown that woven composite sample with 25 pick.cm-1 on DRW 4 projected the highest stress response, 113 MPa. Extensive review indicated that DRW 1 and 4 gave better tensile stress-strain response than the other counterpart. 

Anisotropic constitutive model coupled with damage for Sn-rich solder: Application to SnAgCuSb solder under tensile conditions

2021 ◽  
pp. 105678952110451
Author(s):  
Zhao Zhang ◽  
Sheng Liu ◽  
Kun Ma ◽  
Zhiwen Chen ◽  
Zhengfang Qian ◽  
...  
Keyword(s):  
Tensile Stress ◽  
Constitutive Model ◽  
Damage Evolution ◽  
Mechanical Anisotropy ◽  
Uniaxial Tensile ◽  
Stress Strain ◽  
Proposed Model ◽  
Deformation Behaviors ◽  
Simulation Results ◽  
Anisotropic Constitutive Model

With the rapid development of microelectronics and nanoelectronics, Moore law has significantly slowed down and More than Moore based system in packaging (SiP) is expected to be more and more important, at least for next one to two decades. Mechanical behaviors of interconnect materials such as solders are critical for yield in processes and reliability in testing and operation. Based on the framework of crystal plastic theory and continuum damage mechanics, an anisotropic constitutive model coupled with damage was developed to describe the deformation behaviors of Sn-rich solder. In the proposed model, the inelastic shear rate function was presented by hyperbolic sinusoidal form and power law form. For the damage evolution law, the total shear strain was chosen as the damage function variable. The proposed model was implemented into the general finite element software ABAQUS by forward Euler integration procedure. Some simulation examples were performed to verify the proposed model by comparing the simulation results with the experiments at uniaxial tensile conditions with SnAgCuSb solder chosen as the Sn-rich solder. The tensile stress-strain curves of the simulation results agreed well with the experiments at small strain under different temperatures and strain rates. The simulated stress-rupture stages showed reasonable accuracy with the experiments under four representative tensile conditions. Different tensile stress-strain curves of single grains with orientation of (0-0-0)°, (0-45-0)°, and (0-90-0)° were obtained under the same loading conditions, with an inverse relationship between the tensile strength and elongation. This relationship was in accordance with a referable literature. All these results indicate that the proposed model can describe the deformation behaviors of SnAgCuSb solder well under the tensile conditions in consideration of the mechanical anisotropy and the damage evolution.

Particulate Reinforcement of Polyacrylate Elastomers. II. Mechanical Properties

1975 ◽  
Vol 48 (5) ◽  
pp. 830-844 ◽  
Author(s):  
D. C. Blackley ◽  
M. W. Sheikh
Keyword(s):  
Mechanical Properties ◽  
Tensile Stress ◽  
Surface Treatment ◽  
Strain Curve ◽  
Glass Beads ◽  
Void Content ◽  
Scanning Electron Micrographs ◽  
Stress Strain ◽  
Test Pieces ◽  
The Matrix

Abstract This paper presents and discusses the mechanical properties of crosslinked poly (ethyl acrylates) containing various amounts of microscopic glass beads. The adhesion between the glass beads and the elastomer matrix was varied by subjecting the beads to different surface treatments. That the adhesion is affected by surface treatment has been demonstrated in two ways: (1) Unfilled elastomer sheets have been cast in contact with glass surfaces which had been treated with the same reagents as the beads. The force required to peel the elastomer from the glass was then measured and found to depend strongly upon the surface treatment. (2) Scanning electron micrographs of the ruptured surfaces of used tensile test pieces cut from filled elastomer sheets confirm that surface treatment has a profound effect upon the adhesion between bead and matrix. Results are presented for the hardness and tensile stress-strain properties of elastomers containing various amounts of beads. In all cases, the stiffening effect of the beads increases as the adhesion between beads and matrix is improved. Beads which had been treated in such a way as to minimize the adhesion to the matrix were found to cause an apparent softening of the material as revealed by the tensile stress-strain curve. It has been shown that this effect can be satisfactorily explained if it is assumed that in this case the beads merely serve to increase the void content of the material.

scholarly journals Analysis of Mechanical and Acoustic Emission Characteristics of Rock Materials with Double-Hole Defects Based on Particle Flow Code

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Qi Zhang ◽  
Xiao Wang ◽  
Long-gang Tian ◽  
Dong-mei Huang
Keyword(s):  
Acoustic Emission ◽  
Damage Evolution ◽  
Failure Modes ◽  
Numerical Models ◽  
Strain Range ◽  
Peak Strength ◽  
Particle Flow Code ◽  
Stress Strain ◽  
Rock Materials ◽  
Connection Line

There are a lot of fissures, holes, and other defects in the formation of natural rocks. Under the influence of the external loads, these defects may cause engineering problems. Therefore, it is of great significance to analyze the characteristics of damage evolution of the defective rocks. In the study, the double-hole defective rocks with different angles of the center connection line are considered and the numerical models are established firstly. Then the mechanical behavior and acoustic emission (AE) characteristics are analyzed systematically. Finally the laws of damage evolution of the defective rock materials are investigated based on the AE characteristics. The research results show that the stress-strain behavior of the defective rocks can be divided into elastic stage, plastic stage and failure stages. The characteristics of acoustic emission evolution and laws of damage evolution are closely related to the stress-strain relationship. The elastic modulus of the double-hole defective rocks is similar with different angles of the center connection line, but the peak strength is different. The shape of the peak strength of these defective rocks is a W type owing to the different failure modes. The influences of different angles of the center connection line on the characteristics of AE evolution include the maximum events number, the strain value of the initial AE events and the maximum AE events, and the strain range of the serious AE events. Different angles of the center connection line have different influences on the laws of damage evolution of the double-hole defective rocks.

First Principles Study on the TiN/BN/TiN Interface

2011 ◽  
Vol 110-116 ◽  
pp. 1020-1023 ◽  
Author(s):  
Bao Jun Wang ◽  
Fei Xie ◽  
Ke Jun Jia
Keyword(s):  
Tensile Strength ◽  
Tensile Stress ◽  
First Principles ◽  
Calculation Method ◽  
First Principles Calculation ◽  
Strain Response ◽  
Ideal Strength ◽  
Stress Strain ◽  
Electronic Density ◽  
Friedel Oscillations

To obtain a understanding of the deform mechanism and ideal strength in superhard nanocomposites nc-TiN/a-BN. we studied, using the first-principles calculation method, the geometrical stucture, the electronic density and the tensile stress-strain response of a theoretical interfacial system TiN/BN/TiN, which consists of two TiN slabs and one sandwiched BN monolayer. The calculated results show that Friedel oscillations weaken the Ti-N interplanar bonds next to the interface, where decohesion happens. A comparison with the TiN/SiN/TiN interface was done, showing that the orientation has the huger influence on the tensile strength of TiN/BN/TiN interface.

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