A Constitutive Model for the Inelastic Multiaxial Response of Rene’ 80 at 871C and 982C

1990 ◽  
Vol 112 (2) ◽  
pp. 241-246 ◽  
Author(s):  
D. C. Stouffer ◽  
V. G. Ramaswamy ◽  
J. H. Laflen ◽  
R. H. Van Stone ◽  
R. Williams
Keyword(s):  
Constitutive Model ◽  
Experimental Results ◽  
Uniaxial Loading ◽  
Experimental Program ◽  
Multiaxial Loading ◽  
Loading Conditions ◽  
Nonproportional Loading ◽  
Material Parameters ◽  
State Variable

This paper contains an extension of the uniaxial state variable constitutive model of Ramaswamy et al. (1988) to the case of multiaxial loading. The correlation between uniaxial and multiaxial loading conditions is achieved through the assumptions of material isotropy and conservation of inelastic volume. The multiaxial extension is based only on the material parameters evaluated from uniaxial loading. The research is accompanied by a multiaxial experimental program to evaluate the response of Rene’ 80 at 871°C and 982° C. Experiments in the program include torsion, proportional axial and torsion, and nonproportional loading. It was shown experimentally that there is no extra hardening from the multiaxial loading than results from uniaxial loading. Further, it is shown that the multiaxial model is successful in predicting the experimental results using only the parameters determined from the uniaxial experiments.

Peridynamic Modeling of Hyperelastic Membrane Deformation

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
D. J. Bang ◽  
E. Madenci
Keyword(s):  
Energy Density ◽  
Strain Energy Density ◽  
Strain Energy ◽  
Equations Of Motion ◽  
Uniaxial Loading ◽  
Density Functions ◽  
Loading Conditions ◽  
Element Analysis ◽  
Material Parameters ◽  
Loading Case

This study concerns the development of peridynamic (PD) strain energy density functions for a Neo-Hookean type membrane under equibiaxial, planar, and uniaxial loading conditions. The material parameters for each loading case are determined by equating the PD strain energy density to that of the classical continuum mechanics. The PD equations of motion are derived based on the Neo-Hookean model under the assumption of incompressibility. Numerical results concern the deformation of a membrane with a defect in the form of a hole, a crack, and a rigid inclusion under equibiaxial, planar, and uniaxial loading conditions. The PD predictions are verified by comparison with those of finite element analysis.

Quantification of Numerical Stiffness for a Unified Viscoplastic Constitutive Model

1990 ◽  
Vol 112 (3) ◽  
pp. 271-276 ◽  
Author(s):  
S. M. Arnold
Keyword(s):  
Constitutive Model ◽  
State Space ◽  
Copper Alloy ◽  
Jacobian Matrix ◽  
The State ◽  
Maximum Difference ◽  
Material Parameters ◽  
State Variable ◽  
Variable Approach ◽  
State Point

Here the question of numerical stiffness pertaining to a unified viscoplastic constitutive model is examined. The viewpoint maintained throughout this study is the state variable approach. Stiffness is quantified by examining, analytically, the eigenvalues of the associated Jacobian matrix. Specific results, in the form of stiffness contours, for the material parameters characterizing the copper alloy NARloy-Z are presented in the associated uniaxial state space. The results indicate that the potential for numerical stiffness does exist, however the severity is highly dependent upon the location of the state point within the state space. Finally a qualitative analogy between the maximum difference in stiffness indicating eigenvalues and the G vectors of the corresponding state space is suggested.

Modeling the Ratcheting Phenomenon in an Austenitic Steel at Room Temperature

2000 ◽  
Author(s):  
A. S. Zaki ◽  
H. Ghonem
Keyword(s):  
Plastic Strain ◽  
Constitutive Model ◽  
Austenitic Steel ◽  
Room Temperature ◽  
Polycrystalline Material ◽  
Kinematic Hardening ◽  
Experimental Results ◽  
Experimental Program ◽  
Model Parameters ◽  
Proposed Model

Abstract This paper describes the cyclic accumulative plastic strain in a polycrystalline material when subjected to loading conditions promoting ratcheting behavior. For this purpose, a unified viscoplastic constitutive model based on non-linear kinematic hardening formulation is implemented. Identification of the model parameters was carried out using an experimental program that included monotonic, cyclic and relaxation testing. Simulation of the material response using the proposed model is compared with experimental results for the same loading. This comparison is used to evaluate the model validity.

NESC VII European Project: Demonstration of Warm Pre-Stressing Effect in Biaxial Loading Conditions: Bending Tests on 18MND5 Cruciform Specimens and Their Interpretation

2012 ◽  
Author(s):  
C. Jacquemoud ◽  
T. Yuritzinn ◽  
S. Marie ◽  
D. Moinereau ◽  
M. Nédélec ◽  
...  
Keyword(s):  
Cleavage Fracture ◽  
Biaxial Loading ◽  
Experimental Results ◽  
Experimental Program ◽  
Loading Conditions ◽  
Bending Tests ◽  
Loading Cycle ◽  
European Project

In the framework of the NESC VII European project, a large experimental program has been dedicated to characterize the Warm Pre-Stressing (WPS) effect in different testing configurations. One of the CEA (France) contributions to this project is the realization of five point bending tests on large cruciform specimens considering different WPS loading cycles. The five cruciform specimens, sponsored by EDF (France) and IRSN (France), are made of 18MND5 steel. Two of them have been tested on a same LCF (Load-Cool-Fracture) loading cycle and two others on the same LCTF (Load-Cool-Transient-Fracture) loading cycle. The experimental results presented in this paper give a successful demonstration of the WPS effect in biaxial loading conditions either on a LCF or on a LCTF cycle. During the test interpretations, different models have then been tested and compared in order to evaluate their ability to predict the cleavage fracture in the case of different WPS loading cycles. They all provide very conservative predictions whatever loading cycle is concerned.

Application of an Internal Variable Constitutive Model to Predict Creep Response of an Aluminum Alloy Under Multiaxial Loading

1989 ◽  
Vol 56 (3) ◽  
pp. 514-518 ◽  
Author(s):  
I. U. Mahmood ◽  
M. O. Faruque ◽  
M. M. Zaman
Keyword(s):  
Aluminum Alloy ◽  
Constitutive Model ◽  
Strain Rate ◽  
Creep Strain ◽  
Internal Variable ◽  
Experimental Results ◽  
Creep Strain Rate ◽  
Multiaxial Loading ◽  
Creep Response ◽  
Piecewise Linearity

This paper discusses the application of an internal variable, creep constitutive model, where the concept of piecewise linearity in the effective stress-creep strain rate relationship is utilized. Since the concept of piecewise linearity is assumed, an explicit functional form for creep strain rate at all levels of stress and temperature is not required. The aforementioned constitutive model is used to predict the creep response of an aluminum alloy (2618-T61) at 200°C and subjected to multiaxial loading. The results are compared with available experimental results. The model shows excellent agreement in the trend of creep response. The quantitative values also agree quite good with the experimental results.

Constitutive Model for Concrete under Multiaxial Loading Conditions

2010 ◽  
Vol 163-167 ◽  
pp. 1171-1174 ◽  
Author(s):  
Li Sun ◽  
Wei Min Huang ◽  
Hendra Purnawali
Keyword(s):  
Shape Memory Alloy ◽  
Constitutive Model ◽  
Shape Memory ◽  
Yield Surface ◽  
Crystalline Material ◽  
Multiaxial Loading ◽  
Loading Conditions ◽  
Stress Strain ◽  
Strain Relationship

In this paper we present a new constitutive model for concrete. The framework is originally proposed for shape memory alloy, a kind of crystalline material. We show how to apply this framework for non-crystalline material: concrete. The resulting yield surface and stress-strain relationship are compared with that of experiment reported in the literature.

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