Plasticity Analysis of Fibrous Composites

1982 ◽  
Vol 49 (2) ◽  
pp. 327-335 ◽  
Author(s):  
G. J. Dvorak ◽  
Y. A. Bahei-El-Din
Keyword(s):  
Volume Fraction ◽  
Mechanical Load ◽  
Kinematic Hardening ◽  
Small Diameter ◽  
Local Stress ◽  
Plastic Behavior ◽  
Elastic Plastic ◽  
Elastic Filaments ◽  
Stress Concentration Factors ◽  
Hardening Rules

The elastic-plastic behavior of composites consisting of aligned, continuous elastic filaments and an elastic-plastic matrix is described in terms of constituent properties, their volume fractions, and mutual constraints between the phases indicated by the geometry of the microstructure. The composite is modeled as a continuum reinforced by cylindrical fibers of vanishingly small diameter which occupy a finite volume fraction of the aggregate. In this way, the essential axial constraint of the phases is retained. Furthermore, the local stress and strain fields are uniform. Elastic moduli, yield conditions, hardening rules, and overall instantaneous compliances, as well as instantaneous stress concentration factors are derived. Specific results are obtained for the case of a Mises-type matrix which obeys the Prager-Ziegler kinematic hardening rule. Any multiaxial mechanical load may be applied. Comparisons are made between the present results and certain other theories.

Elastic-Plastic Analysis of Fretting Contacts

2015 ◽  
Vol 642 ◽  
pp. 248-252
Author(s):  
Chang Hung Kuo
Keyword(s):  
Kinematic Hardening ◽  
Carbon Steels ◽  
Plastic Behavior ◽  
Rule Based ◽  
Elastic Plastic ◽  
Hardening Rule ◽  
Chaboche Model ◽  
Plastic Analysis ◽  
Finite Element Procedure ◽  
Elastic Shakedown

A finite element procedure is implemented for the elastic-plastic analysis of carbon steels subjected to reciprocating fretting contacts. The nonlinear kinematic hardening rule based on Chaboche model is used to model the cyclic plastic behavior in fretting contacts. The results show that accumulation of plastic strains, i.e. ratchetting, may occur near the contact edge while elastic shakedown is likely to take place in substrate.

Elastic-plastic finite element analysis of hollow tubes with axially loaded axisymmetric internal projections

1993 ◽  
Vol 28 (3) ◽  
pp. 187-196 ◽  
Author(s):  
S J Hardy ◽  
A R Gowhari-Anaraki
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Elastic Stress ◽  
Low Cycle Fatigue ◽  
Kinematic Hardening ◽  
Isotropic Hardening ◽  
Published Data ◽  
Elastic Plastic ◽  
Concentration Factors ◽  
Stress Concentration Factors

The finite element method is used to study the monotonic and cyclic elastic-plastic stress and strain characteristics of hollow tubes with axisymmetric internal projections subjected to monotonic and repeated axial loading. Two geometries having low and high elastic stress concentration factors are considered in this investigation, and the results are complementary to previously published data. For cyclic loading, three simple material behaviour models, e.g., elastic-perfectly-plastic, isotropic hardening, and kinematic hardening are assumed. All results have been normalized with respect to material properties so that they can be applied to all geometrically similar components from other materials which may be represented by the same material models. Finally, normalized maximum monotonic strain and steady state strain range, predicted in the present investigation and from previously published data, are plotted as a function of the nominal load for different material hardening assumptions and different elastic stress concentration factors. These plots can be used in the low cycle fatigue design of such geometrically similar components.

scholarly journals On the Plastic and Viscoplastic Constitutive Equations—Part I: Rules Developed With Internal Variable Concept

1983 ◽  
Vol 105 (2) ◽  
pp. 153-158 ◽  
Author(s):  
J. L. Chaboche ◽  
G. Rousselier
Keyword(s):  
Plastic Strain ◽  
Kinematic Hardening ◽  
Strain Tensor ◽  
Internal Variable ◽  
Cyclic Behavior ◽  
Internal Variables ◽  
Plastic Behavior ◽  
Hardening Rules ◽  
Plastic Strain Tensor ◽  
Natural Description

The description of monotonic and cyclic behavior of material is possible by generalizing the internal stress concept by means of a set of internal variables. In this paper the classical isotropic and kinematic hardening rules are briefly discussed, using present plastic strain tensor and cumulated plastic strain as hardening variables. Some additional internal variables are then proposed, giving rise to many possibilities. What is called the “nonlinear kinematic hardening” leads to a natural description of the nonlinear plastic behavior under cyclic loading, but is connected to other concepts such as the Mroz’s model, limited to only two surfaces, and similarities with other approaches are pointed out in the context of a generalization of this rule to viscoplasticity.

Elastic and Plastic Response of Perforated Metal Sheets With Different Porosity Architectures

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Hamed Khatam ◽  
Linfeng Chen ◽  
Marek-Jerzy Pindera
Keyword(s):  
Elastic Moduli ◽  
Volume Fraction ◽  
Stress Transfer ◽  
Local Stress ◽  
Shear Loading ◽  
Homogenization Theory ◽  
Plastic Response ◽  
Elastic Plastic ◽  
Aluminum Sheets ◽  
Metal Sheets

The effects of porosity architecture and volume fraction on the homogenized elastic moduli and elastic-plastic response of perforated thin metal sheets are investigated under three fundamental loading modes using an efficient homogenization theory. Steel and aluminum sheets weakened by circular, hexagonal, square, and slotted holes arranged in square and hexagonal arrays subjected to inplane normal and shear loading are considered with porosity volume fractions in the range 0.1–0.6. Substantial variations are observed in the homogenized elastic moduli with porosity shape and array type. The differences are rooted in the stress transfer mechanism around traction-free porosities whose shape and distribution play major roles in altering the local stress fields and thus the homogenized response in the elastic-plastic domain. This response is characterized by four parameters that define different stages of micro- and macrolevel yielding. The variations in these parameters due to porosity architecture and loading direction provide useful data for design purposes under monotonic and cyclic loading.

A Comparison of the Capability of Four Hardening Rules to Predict a Material’s Plastic Behavior

1976 ◽  
Vol 98 (1) ◽  
pp. 66-74 ◽  
Author(s):  
B. Hunsaker ◽  
D. K. Vaughan ◽  
J. A. Stricklin
Keyword(s):  
Biaxial Loading ◽  
Kinematic Hardening ◽  
Finite Difference Methods ◽  
Strain Analysis ◽  
Small Strain ◽  
Isotropic Hardening ◽  
Plastic Behavior ◽  
Metal Structures ◽  
Hardening Rules ◽  
Uniaxial And Biaxial Loading

Isotropic hardening, Prager-Ziegler kinematic hardening, the Mroz model, and the mechanical sublayer model are investigated to determine which of these hardening rules are better suited for use in nonlinear small strain analysis of metal structures by the finite element or finite difference methods. The material response predicted by each hardening rule is compared with experiments from the literature for uniaxial and biaxial loading of metals. Computer storage requirements for each model are then presented along with the results of the elastic-plastic analysis of an impulsively loaded plate. Recommendations are then made of appropriate hardening rules based on material characteristics and loading conditions.

Plasticity Analysis of Laminated Composite Plates

1982 ◽  
Vol 49 (4) ◽  
pp. 740-746 ◽  
Author(s):  
Y. A. Bahei-El-Din ◽  
G. J. Dvorak
Keyword(s):  
Composite Laminates ◽  
Laminated Composite ◽  
Composite Plates ◽  
Laminated Plates ◽  
Plastic Behavior ◽  
Elastic Plastic ◽  
Local Stresses ◽  
The Individual ◽  
Hardening Rules ◽  
Yield Conditions

Elastic-plastic behavior of symmetric metal-matrix composite laminates is analyzed for the case of in-plane mechanical loading. The overall response of the laminate at each instant is derived from the elastic-plastic deformation of the individual fibrous layers, and from their mutual constraints. Constitutive equations of the laminated plates are presented in terms of initial yield conditions, hardening rules, and instantaneous compliances. Local stresses, hardening parameters, and strains are found in each lamina and in the fiber and matrix phases within each lamina. Specific results are obtained with the continuum model of elastic-plastic fibrous composites [1] which has been recently developed by the authors. Comparisons of analytical results with experimental measurements are made for certain laminated plates.

A Comparison Between Two Models That Predict the Elastic-Plastic Behavior of Particulate Metal Matrix Composites Under Multiaxial Fatigue Type Loading

Materials ◽  
2003 ◽  
Author(s):  
Gbadebo Moses Owolabi ◽  
Meera N. K. Singh
Keyword(s):  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Volume Fraction ◽  
Constitutive Relations ◽  
Multiaxial Fatigue ◽  
Cyclic Plasticity ◽  
Plastic Behavior ◽  
Matrix Composites ◽  
Elastic Plastic ◽  
Particulate Metal

This paper is an effort to first modify two cyclic plasticity models developed for homogeneous metals to address the heterogeneous nature of particulate metal matrix composites (PMMCs), and subsequently to evaluate the resulting relations both theoretically and experimentally. Specifically, using the original Mro´z model and the endochronic theory of plasticity as their bases, two sets of elastic-plastic constitutive relations are identified. These sets of relations account for the interaction in stress fields between adjacent particles in PMMCs. The behavior predicted by each model is compared with experimental results obtained from a series of uniaxial and biaxial (tension-torsion) tests performed on circular specimens made of the 6061/Al2O3/20p-T6 PMMCs with 20% volume fraction of particles. The materials are tested for a variety of applied monotonic and cyclic loading paths.

Modeling and Identification of Elastic-Plastic Systems Using the Distributed-Element Model

1997 ◽  
Vol 119 (4) ◽  
pp. 332-336 ◽  
Author(s):  
Dar-Yun Chiang
Keyword(s):  
Distribution Function ◽  
Bauschinger Effect ◽  
Biaxial Tension ◽  
Kinematic Hardening ◽  
Element Model ◽  
Strength Distribution ◽  
Experimental Results ◽  
Modeling Technique ◽  
Elastic Plastic ◽  
Hardening Rules

A modeling technique is proposed for a class of distributed-element models, which is able to account for the multi-axial Bauschinger effect without any additional kinematic hardening rules. The parameters associated with each of the elements in the model are specified by introducing an appropriate strength distribution function so as to make the model parsimonious in parameters regardless of the number of elements introduced in the model. Validity of the proposed modeling technique, in both modeling and identification of elastic-plastic systems, is demonstrated by biaxial tension-torsion applications using experimental results from the literature.

Elastic-plastic behavior of coldworked holes

1983 ◽  
Author(s):  
H. ARMEN ◽  
A. LEVY ◽  
H. EIDINOFF
Keyword(s):  
Plastic Behavior ◽  
Elastic Plastic
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