Particulate Reinforcement of Polyacrylate Elastomers. III. Swelling Measurements

1975 ◽  
Vol 48 (5) ◽  
pp. 845-859 ◽  
Author(s):  
D. C. Blackley ◽  
M. W. Sheikh
Keyword(s):  
Tensile Stress ◽  
Crosslink Density ◽  
Glass Beads ◽  
Surface Treatments ◽  
Swelling Behavior ◽  
Force Measurements ◽  
Stress Strain ◽  
Particulate Reinforcement ◽  
The Matrix ◽  
Peel Force

Abstract This paper presents and discusses results which have been obtained for the swelling in chlorobenzene 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. The swelling behavior has been found to correlate very closely with the extent of adhesion as judged by peel force measurements and tensile stress-strain properties reported previously. In the case of beads showing pronounced adhesion to the matrix, restrictions on swelling have been interpreted in terms of an apparent enhancement of crosslink density by the reactive beads.

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.

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 Predictive Computational Model for Damage Behavior of Metal-Matrix Composites Emphasizing the Effect of Particle Size and Volume Fraction

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2143
Author(s):  
Shaimaa I. Gad ◽  
Mohamed A. Attia ◽  
Mohamed A. Hassan ◽  
Ahmed G. El-Shafei
Keyword(s):  
Finite Element ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Volume Fraction ◽  
Particulate Composites ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Zone Method ◽  
Stress Strain ◽  
The Matrix

In this paper, an integrated numerical model is proposed to investigate the effects of particulate size and volume fraction on the deformation, damage, and failure behaviors of particulate-reinforced metal matrix composites (PRMMCs). In the framework of a random microstructure-based finite element modelling, the plastic deformation and ductile cracking of the matrix are, respectively, modelled using Johnson–Cook constitutive relation and Johnson–Cook ductile fracture model. The matrix-particle interface decohesion is simulated by employing the surface-based-cohesive zone method, while the particulate fracture is manipulated by the elastic–brittle cracking model, in which the damage evolution criterion depends on the fracture energy cracking criterion. A 2D nonlinear finite element model was developed using ABAQUS/Explicit commercial program for modelling and analyzing damage mechanisms of silicon carbide reinforced aluminum matrix composites. The predicted results have shown a good agreement with the experimental data in the forms of true stress–strain curves and failure shape. Unlike the existing models, the influence of the volume fraction and size of SiC particles on the deformation, damage mechanism, failure consequences, and stress–strain curve of A359/SiC particulate composites is investigated accounting for the different possible modes of failure simultaneously.

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.

Tensile stress-strain behavior of lightly cemented sand

1993 ◽  
Vol 30 (7) ◽  
pp. 711-714 ◽  
Author(s):  
R.N. Dass ◽  
S.C. Yen ◽  
V.K. Puri ◽  
B.M. Das ◽  
M.A. Wright
Keyword(s):  
Tensile Stress ◽  
Stress Strain ◽  
Cemented Sand ◽  
Strain Behavior

scholarly journals Tensile Behaviour of FRCM Composites for Strengthening of Masonry Structures—An Experimental Investigation

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3626
Author(s):  
Łukasz Hojdys ◽  
Piotr Krajewski
Keyword(s):  
Tensile Stress ◽  
Strain Curve ◽  
Tensile Tests ◽  
Tensile Failure ◽  
Tensile Behaviour ◽  
Masonry Structures ◽  
Stress Strain ◽  
Flexural Tensile Strength ◽  
Cracking Pattern ◽  
Direct Tensile

This paper presents the results of direct tensile tests performed on six different FRCM (fabric reinforced cementitious matrix) strengthening systems used for masonry structures. The emphasis was placed on the determination of the mechanical parameters of each tested system and a comparison of their tensile behaviour in terms of first crack stress, ultimate stress, ultimate strain, cracking pattern, failure mode and idealised tensile stress-strain curve. In addition to the basic mechanical tensile parameters, accidental load eccentricities, matrix tensile strengths, and matrix modules of elasticity were estimated. The results of the tests showed that the tensile behaviour of FRCM composites strongly depends on the parameters of the constituent materials (matrix and fabric). In the tests, tensile failure of reinforcement and fibre slippage within the matrix were observed. The presented research showed that the accidental eccentricities did not substantially affect the obtained results and that the more slender the specimen used, the more consistent the obtained results. The analysis based on a rule of mixtures showed that the direct tensile to flexural tensile strength ratio of the matrixes used in the test was 0.2 to 0.4. Finally, the tensile stress–strain relationship for the tested FRCMs was idealised by a bi- or tri-linear curve.

Principle of Strength Reinforcement in Filled Rubbers

1967 ◽  
Vol 40 (5) ◽  
pp. 1337-1363 ◽  
Author(s):  
A. E. Oberth
Keyword(s):  
Particle Size ◽  
Crosslink Density ◽  
High Modulus ◽  
Stress Concentrations ◽  
Volume Increase ◽  
The Matrix ◽  
Filled Rubbers ◽  
Filler Particles ◽  
Tear Properties ◽  
Properties Of Composites

Abstract Effects of filler on mechanical properties of composites result from stress concentrations developed in the matrix and filler particles. Stress concentrations in filler particles relieve stress in the matrix which, under a given load, deforms less than it would in absence of filler. This accounts for high modulus as well as strength reinforcement in filled materials. Stress concentration in the matrix, decreasing with increasing content of filler, is responsible for internal tearing of composites. Magnitude of this internal tearing, which can be measured by volume increase of a specimen under strain, depends on many factors such as: shape of filler, orientation of filler particles, particle size, particle size distribution, nature of boundary layer between filler and matrix, crosslink density and tear properties of the matrix, as well as environmental pressure in the test. High dilatation results in low tensile strength of the composite and conversely if dilatation is suppressed maximum strength reinforcement is obtained.

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