Elastic Behavior of Laminated Flexible Composites Under Finite Deformation

This paper examines the nonlinear elastic behaviour of flexible composites under finite deformation. The constitutive relations have been derived based on a strain-energy density which, in a fourth-order polynomial form, is assumed to be a function of the lagrangian strain components referring to the initial principal material coordinates. The constitutive equations thus obtained are verified by the following experiments: (1) off-axis tension and simple shear for unidirectional composites, and (2) uniaxial tension for flexible composites with wavy fibres. Good agreement has been found between the theory and experiments.

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Constitutive Law of Finite Deformation Elastoplasticity With Proportional Loadings

Journal of Pressure Vessel Technology ◽

10.1115/1.4024581 ◽

2013 ◽

Vol 135 (6) ◽

Cited By ~ 1

Author(s):

H. Darijani ◽

R. Naghdabadi

Keyword(s):

Constitutive Equation ◽

Finite Deformation ◽

Constitutive Models ◽

Pressure Vessels ◽

Constitutive Law ◽

Elastic Behavior ◽

Plastic Behavior ◽

Proportional Loading ◽

Von Mises ◽

Plastic Parts

In this paper, decomposition of the total strain into elastic and plastic parts is investigated for extension of elastic-type constitutive models to finite deformation elastoplasticity. In order to model the elastic behavior, a Hookean-type constitutive equation based on the logarithmic strain is considered. Based on this constitutive equation and assuming the deformation theory of Hencky as well as the yield criteria of von Mises, the elastic-plastic behavior of materials at finite deformation is modeled in the case of the proportional loading. Moreover, this elastoplastic model is applied in order to determine the stress distribution in thick-walled cylindrical pressure vessels at finite deformation elastoplasticity.

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Finite Elastic Behavior of Flexible Fabric Composite Under Biaxial Loading

Journal of Applied Mechanics ◽

10.1115/1.2791494 ◽

1999 ◽

Vol 66 (3) ◽

pp. 631-638 ◽

Cited By ~ 15

Author(s):

S.-Y. Luo ◽

A. Mitra

Keyword(s):

Mechanical Properties ◽

Constitutive Equations ◽

Strain Energy ◽

Biaxial Loading ◽

Elastic Behavior ◽

Flexible Composites ◽

Geometrical Nonlinearities ◽

Fabric Composite ◽

Sinusoidal Shape ◽

Good Agreement

A new modeling technique has been introduced to predict the large deformation of flexible composites reinforced by plain-weave fabrics under biaxial loading. The only input required for calculations are the mechanical properties of the constituents and the fabric geometry. The constitutive equations are derived based on a strain energy approach, where fiber and matrix are accounted separately and the curved yarns are assumed to be in sinusoidal shape. Both material and geometrical nonlinearities are considered in the formulation. Good agreement has been found between predictions and experiments under various biaxial loading.

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Finite Deformation and Nonlinear Elastic Behavior of Flexible Composites

Journal of Applied Mechanics ◽

10.1115/1.3173621 ◽

1988 ◽

Vol 55 (1) ◽

pp. 149-155 ◽

Cited By ~ 33

Author(s):

Shen-Yi Luo ◽

Tsu-Wei Chou

Keyword(s):

Present Theory ◽

Elastic Behavior ◽

Stress Strain ◽

Flexible Composites ◽

Elastomeric Matrix ◽

Eulerian Description ◽

Stress Strain Relation ◽

Nonlinear Stress ◽

Material Nonlinear ◽

Nonlinear Elastic

The flexible composites discussed in this paper are composed of continuous fibers in an elastomeric matrix. The usable range of deformation of these composites is much larger than that of conventional rigid composites. Due to the material as well as geometric factors, the stress-strain relations for these composites are generally nonlinear under finite deformations. A constitutive model has been developed based upon the Eulerian description. The material nonlinear stress-strain relation is derived by using the stress energy density referring to the deformed volume. The stretching-shear coupling and the effects of the in-plane reorientation of fibers are also considered in the theoretical analysis. Comparisons are made between predictions of the present theory and experimental data for tirecord/rubber and Kevlar/silicone-elastomer flexible composite laminae; very good correlations have been found.

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Electron Microscopy of Metal-Matrix Composites

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100069016 ◽

1970 ◽

Vol 28 ◽

pp. 404-405

Author(s):

A. Lawley ◽

M. R. Pinnel ◽

A. Pattnaik

Keyword(s):

Electron Microscopy ◽

Metal Matrix Composites ◽

Metal Matrix ◽

Critical Evaluation ◽

Elastic Behavior ◽

Matrix Composites ◽

Directionally Solidified ◽

Fracture Characteristics ◽

Broad Program

As part of a broad program on composite materials, the role of the interface on the micromechanics of deformation of metal-matrix composites is being studied. The approach is to correlate elastic behavior, micro and macroyielding, flow, and fracture behavior with associated structural detail (dislocation substructure, fracture characteristics) and stress-state. This provides an understanding of the mode of deformation from an atomistic viewpoint; a critical evaluation can then be made of existing models of composite behavior based on continuum mechanics. This paper covers the electron microscopy (transmission, fractography, scanning microscopy) of two distinct forms of composite material: conventional fiber-reinforced (aluminum-stainless steel) and directionally solidified eutectic alloys (aluminum-copper). In the former, the interface is in the form of a compound and/or solid solution whereas in directionally solidified alloys, the interface consists of a precise crystallographic boundary between the two constituents of the eutectic.

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Dynamics of Nanoparticle Chain Aggregates of Carbon Under Tension

MRS Proceedings ◽

10.1557/proc-778-u4.4 ◽

2003 ◽

Vol 778 ◽

Author(s):

Rajdip Bandyopadhyaya ◽

Weizhi Rong ◽

Yong J. Suh ◽

Sheldon K. Friedlander

Keyword(s):

Mechanical Properties ◽

Carbon Black ◽

Polymer Film ◽

Elastic Behavior ◽

Small Strains ◽

Transmission Electron ◽

Chain Aggregates ◽

Nanoparticle Chains ◽

Reinforcing Filler

AbstractCarbon black in the form of nanoparticle chains is used as a reinforcing filler in elastomers. However, the dynamics of the filler particles under tension and their role in the improvement of the mechanical properties of rubber are not well understood. We have studied experimentally the dynamics of isolated nanoparticle chain aggregates (NCAs) of carbon made by laser ablation, and also that of carbon black embedded in a polymer film. In situ studies of stretching and contraction of such chains in the transmission electron microscope (TEM) were conducted under different maximum values of strain. Stretching causes initially folded NCA to reorganize into a straight, taut configuration. Further stretching leads to either plastic deformation and breakage (at 37.4% strain) or to a partial elastic behavior of the chain at small strains (e.g. 2.3% strain). For all cases the chains were very flexible under tension. Similar reorientation and stretching was observed for carbon black chains embedded in a polymer film. Such flexible and elastic nature of NCAs point towards a possible mechanism of reinforcement of rubber by carbon black fillers.

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