Assessment of Tensorial and Scalar Damage Models for an Isotropic Thermally Cracked Rock Under Confining Pressure Using Experimental Data: Continuum Damage Mechanics Versus Effective Medium Theory

2021 ◽  
Author(s):  
Louise Olsen-Kettle ◽  
Joel Sarout
Keyword(s):  
Experimental Data ◽  
Damage Mechanics ◽  
Effective Medium Theory ◽  
Continuum Damage Mechanics ◽  
Confining Pressure ◽  
Effective Medium ◽  
Continuum Damage ◽  
Medium Theory ◽  
Damage Models

Study on Continuum Damage Mechanics Model for High Cycle Fatigue

2016 ◽  
Vol 835 ◽  
pp. 564-567
Author(s):  
Xin Tong Shi ◽  
Ying Chun Xiao ◽  
Hong Chen ◽  
Bo Huang
Keyword(s):  
Experimental Data ◽  
Damage Mechanics ◽  
High Cycle Fatigue ◽  
Continuum Damage Mechanics ◽  
Fatigue Loading ◽  
Continuum Damage ◽  
Cycle Fatigue ◽  
Stress Effects ◽  
Mechanics Model ◽  
Proposed Model

A continuum damage mechanics model was proposed to predict the high cycle fatigue life. In order to consider mean stress effects, the Walker correction was introduced in proposed model. The model was verified by experimental data on LC4 and LY12CZ aluminum alloy under high cycle fatigue loading. The results showed that the predicted life of proposed model well correlated with experimental data.

A Unified Continuum Damage Mechanics Model for Predicting the Stress Relaxation Behavior of High-Temperature Bolting

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
J. Q. Guo ◽  
X. T. Zheng ◽  
Y. Zhang ◽  
H. C. Shi ◽  
W. Z. Meng
Keyword(s):  
Experimental Data ◽  
High Temperature ◽  
Stress Relaxation ◽  
Constitutive Equations ◽  
Damage Mechanics ◽  
Continuum Damage Mechanics ◽  
Relaxation Behavior ◽  
Continuum Damage ◽  
Creep Equation ◽  
Stress Relaxation Behavior

Two stress relaxation constitutive models have been developed to predict the stress relaxation behavior for high-temperature bolting according to continuum damage mechanics, Kachanov–Robatnov (K–R), and Othman–Hayhurst (O–H) creep constitutive equations as well as stress relaxation strain equations. To validate the effectiveness of constitutive equations, the predicted results were compared with the experimental data of uniaxial isothermal stress relaxation tests using 1Cr10NiMoW2VNbN steel. The results show that the results obtained by the stress relaxation constitutive model based on the K–R creep equation overestimates the stress relaxation behavior, while the model deduced by the O–H creep equation is more in agreement with the experimental data. Moreover, the stress relaxation damage predicted increases with the increment of initial stress significantly. These indicate that the new models can predict the stress relaxation behavior of high-temperature bolting well.

Anisotropic (Continuum Damage Mechanics)-based multi-mechanism model for semi-crystalline polymer

2016 ◽  
Vol 27 (3) ◽  
pp. 357-386 ◽  
Author(s):  
Walid Ayadi ◽  
Lucien Laiarinandrasana ◽  
Kacem Saï
Keyword(s):  
Experimental Data ◽  
Shape Factor ◽  
Damage Mechanics ◽  
Crystalline Polymer ◽  
Continuum Damage Mechanics ◽  
Degree Of Crystallinity ◽  
Continuum Damage ◽  
Mechanism Model ◽  
Energy Equivalence ◽  
Proposed Model

In this work, the anisotropic damage of semi-crystalline polymers is investigated. The model, developed within a thermodynamic framework, includes the following features: (i) the degree of crystallinity; (ii) the hydrostatic pressure effect; and (iii) the damage anisotropy. The adopted tensorial damage variable is based on the Continuum Damage Mechanics approach under the energy equivalence assumption. For the quantification of the anisotropy, a parameter called “shape factor” is defined as the ratio between the void mean diameter and the void mean height. This parameter is linked to the main axial and the main radial damage components. Experimental data taken from the recent literature using the tomography technique were selected to assess the model capability. Finite element simulations of notched round bar specimens subjected to tensile test stopped at three key loading stages are systematically compared with experimental data. The proposed model was able not only to accurately simulate the macroscopic response of the material, but more interestingly, to reproduce the spatial distribution of the shape factor. This demonstrates the anisotropy effects of the material under study induced at different stages of the deformation.

TUNNELING PERCOLATION MODEL OF THE ELECTRICAL CONDUCTIVITY OF PARTICULATE NANOCOMPOSITES

2009 ◽  
Vol 23 (10) ◽  
pp. 1273-1279 ◽  
Author(s):  
LIU-JUAN ZHU ◽  
WEN-ZHONG CAI ◽  
BO-QIN GU ◽  
SHAN-TUNG TU
Keyword(s):  
Experimental Data ◽  
Electrical Conductivity ◽  
Percolation Theory ◽  
Effective Medium Theory ◽  
Effective Medium ◽  
Percolation Model ◽  
Medium Theory ◽  
Property Correlation ◽  
Conduction Behavior ◽  
Particle Statistics

The nanocomposites consisting of conducting nanoparticles and insulating matrix are studied. A tunneling percolation model is developed for their peculiar conduction behavior based on the equivalent-particle concept. It provides a clear microstructure-property correlation by combining many-particle statistics, effective-medium theory, and classical percolation theory. Its availability is assessed by available experimental data.

Geometry Transferability of Lemaitre's Continuum Damage Mechanics Model in the Plane Stress Specimens

2013 ◽  
Vol 592-593 ◽  
pp. 266-270 ◽  
Author(s):  
Nima Allahverdizadeh ◽  
Andrea Manes ◽  
Marco Giglio ◽  
Andrea Gilioli
Keyword(s):  
Plane Stress ◽  
Damage Mechanics ◽  
Numerical Models ◽  
Damage Model ◽  
High Strength ◽  
Experimental Tests ◽  
Continuum Damage Mechanics ◽  
Failure Behavior ◽  
Continuum Damage ◽  
Damage Models

Different damage mechanics models have been proposed by researchers to calibrate the failure behavior of materials. Continuum damage mechanics (CDM) models are one of the main categories of damage models that can be exploited in numerical simulations. In this paper Lemaitres damage model, has been applied to finite element models of flat specimens. These models allow assessing the geometry transferability of the previously calibrated CDM model investigating in different geometry and loading conditions. Four different types of plane stress specimens have been designed to get different stress triaxialities which cover shear dominant and high triaxiality failure. Experimental tests were also done and the obtained data were critically compared with the results from numerical models. The tested material is Ti-6Al-4V titanium alloy which is a widely used material in aerospace industry because of its high strength and low density.

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