Numerical modeling of the effect of strain rate on the stress-strain relation for soft rock using a 3-d elastic visco-plastic model

2004 ◽  
Vol 41 (3) ◽  
pp. 423 ◽  
Author(s):  
H.J. Liao ◽  
W.C. Pu ◽  
J.H. Yin ◽  
M. Akaishi ◽  
A. Tonosaki
Keyword(s):  
Numerical Modeling ◽  
Strain Rate ◽  
Soft Rock ◽  
Stress Strain ◽  
Plastic Model ◽  
Strain Relation ◽  
Stress Strain Relation

Analytical Formulation of a Rate and Temperature Dependent Stress-Strain Relation

1979 ◽  
Vol 101 (3) ◽  
pp. 254-257 ◽  
Author(s):  
A. Merzer ◽  
S. R. Bodner
Keyword(s):  
Plastic Strain ◽  
Strain Rate ◽  
Uniaxial Stress ◽  
Plastic Strain Rate ◽  
Isotropic Hardening ◽  
Stress Strain ◽  
Rate Dependent ◽  
Strain Relation ◽  
Strain And Strain Rate ◽  
Stress Strain Relation

The equation for plastic strain rate in the Bodner-Partom viscoplastic formulation is integrated under conditions of uniaxial stress, constant plastic strain rate, and isotropic hardening to give an analytical expression for the stress as a function of plastic strain and strain rate. Temperature dependence is introduced which leads to a general relationship between stress, strain, strain rate, and temperature. The resulting equation indicates an asymptotic saturation stress whose dependence on strain rate and temperature appears to agree with experimental results. Strain hardening given by the analytical equation also seems to be consistent with experiments. A possible new definition of yield stress is a consequence of the rate dependent stress-strain relation.

Numerical Analysis on Usability of SHPB to Characterize Dynamic Stress–Strain Relation of Metal Foam

2017 ◽  
Vol 09 (05) ◽  
pp. 1750075 ◽  
Author(s):  
Beixin Xie ◽  
Liqun Tang ◽  
Yiping Liu ◽  
Zhenyu Jiang ◽  
Zejia Liu
Keyword(s):  
Strain Rate ◽  
Dynamic Stress ◽  
Metal Foam ◽  
Test Method ◽  
Specimen Thickness ◽  
Strain Rates ◽  
Stress Strain ◽  
Deformation Localization ◽  
Strain Relation ◽  
Stress Strain Relation

Split Hopkinson pressure bar (SHPB) technique is the most important test method to characterize dynamic stress–strain relations of various materials at different strain rates, and this technique requires uniform deformation of specimen during the experiment. However, some studies in recent years have found obvious deformation localization within metal foam specimens in SHPB tests, which may significantly affect the reliability of the results. Usability of SHPB to characterize dynamic stress–strain relation of metal foam becomes doubtful. In this paper, based on experimental verification, we carried out numerical simulative SHPB tests to study the problem, in which the metal foam specimens were modeled to have 3D meso structures with properties of their matrix material. Numerical simulative SHPB tests of aluminum foam specimens with varying thickness at different strain rates were performed. Deformation distribution in each local region of the specimen was examined and a concept of “effective specimen” was presented. Appropriate specimen thickness and range of testing strain rate were suggested based on quantitative analysis. Finally, we recommended a method how to revise the nominal strain and strain rate measured by traditional SHPB method to acquire the reliable dynamic stress–strain relation.

Experimental Study of the Effects of Geometry and Strain Rate on Dynamic Behavior of Axial Crushing Honeycomb

2016 ◽  
Vol 715 ◽  
pp. 86-92
Author(s):  
Tsutomu Umeda ◽  
Kohei Kataoka ◽  
Koji Mimura
Keyword(s):  
Strain Rate ◽  
Rate Sensitivity ◽  
Honeycomb Structure ◽  
Stress Strain ◽  
Axial Crushing ◽  
Buckling Stress ◽  
Branch Angle ◽  
Strain Relation ◽  
Stress Strain Relation ◽  
The Mean

The axial crushing behavior of some metal honeycombs, of which materials show different characteristics including the strain rate sensitivity with each other, was studied with varying the branch angle at the node of honeycomb, and the effects of geometry and strain rate on that as an energy absorber were discussed. Honeycomb specimens of different branch angles were made by the corrugation technique, and axial crushing tests were carried out under low-speed and impact loading conditions. Then, the effects of the characteristics of stress – strain relation of the material itself, the branch angle and the strain rate on the stress – strain relation of honeycomb structure and the mean buckling stress were examined. The tendency of deterioration in the plateau load or the mean buckling stress due to the irregularity of branch angle was evaluated with considering the influence of boundary conditions by the aid with the numerical simulation. It was also found that the strain rate dependence of metal honeycomb is greatly relaxed as compared with that of the material itself.

scholarly journals Limit analysis of narrow support elements in W7-X considering the serration effect of the stress–strain relation at 4K

2011 ◽  
Vol 86 (6-8) ◽  
pp. 1462-1465 ◽  
Author(s):  
E. Briani ◽  
C. Gianini ◽  
F. Lucca ◽  
A. Marin ◽  
J. Fellinger ◽  
...  
Keyword(s):  
Limit Analysis ◽  
Stress Strain ◽  
Strain Relation ◽  
Stress Strain Relation

Analytical stress-strain relation for soils

2021 ◽  
Author(s):  
Kristian Krabbenhoft ◽  
J. Wang
Keyword(s):  
Test Data ◽  
Narrow Range ◽  
Strain Range ◽  
Data Sets ◽  
Soil Tests ◽  
Stress Strain ◽  
Strain Relation ◽  
Stress Strain Relation ◽  
Typical Test ◽  
Typical Soil

A new stress-strain relation capable of reproducing the entire stress-strain range of typical soil tests is presented. The new relation involves a total of five parameters, four of which can be inferred directly from typical test data. The fifth parameter is a fitting parameter with a relatively narrow range. The capabilities of the new relation is demonstrated by the application to various clay and sand data sets.

Stress-Strain Relations and Vibrations of a Granular Medium

1957 ◽  
Vol 24 (4) ◽  
pp. 585-593
Author(s):  
J. Duffy ◽  
R. D. Mindlin
Keyword(s):  
Energy Dissipation ◽  
Contact Forces ◽  
Face Centered Cubic ◽  
Stress Strain ◽  
Differential Stress ◽  
Elastic Bodies ◽  
Strain Relation ◽  
Stress Strain Relation ◽  
Face Centered ◽  
Experimental Values

Abstract A differential stress-strain relation is derived for a medium composed of a face-centered cubic array of elastic spheres in contact. The stress-strain relation is based on the theory of elastic bodies in contact, and includes the effects of both normal and tangential components of contact forces. A description is given of an experiment performed as a test of the contact theories and the differential stress-strain relation derived from them. The experiment consists of a determination of wave velocities and the accompanying rates of energy dissipation in granular bars composed of face-centered cubic arrays of spheres. Experimental results indicate a close agreement between the theoretical and experimental values of wave velocity. However, as in previous experiments with single contacts, the rate of energy dissipation is found to be proportional to the square of the maximum tangential contact force rather than to the cube, as predicted by the theory for small amplitudes.

Sign in / Sign up

Export Citation Format

Share Document