Use of the Iosipescu test for the identification of shear damage evolution laws of an orthotropic composite

2017 ◽  
Vol 174 ◽  
pp. 319-328 ◽  
Author(s):  
Thomas Bru ◽  
Robin Olsson ◽  
Renaud Gutkin ◽  
Gaurav M. Vyas
Keyword(s):  
Damage Evolution ◽  
Orthotropic Composite ◽  
Shear Damage ◽  
Evolution Laws ◽  
Iosipescu Test

Lode angle dependency due to anisotropic damage

2020 ◽  
pp. 105678952094856
Author(s):  
A Mattiello ◽  
R Desmorat
Keyword(s):  
Plastic Strain ◽  
Damage Evolution ◽  
Time Integration ◽  
Anisotropic Damage ◽  
Proportional Loading ◽  
Isotropic Materials ◽  
Damage Models ◽  
Evolution Laws ◽  
Lode Angle ◽  
Fully Coupled

The lode angle dependency introduced by anisotropic damage evolution laws is analyzed in detail for initially isotropic materials. Many rupture criteria are obtained, under the proportional loading assumption, by the time integration of different anisotropic damage evolution laws [Formula: see text] among the three existing families: strain governed, stress governed and plastic strain governed. The cross-analysis of path independent rupture criteria and of anisotropic damage evolution laws finally allows us to improve the Lode angle dependency of (fully coupled) anisotropic damage models.

On Microscopic Thermodynamic Mechanisms of Damage Evolution Laws

2005 ◽  
Vol 14 (3) ◽  
pp. 261-293 ◽  
Author(s):  
Qiang Yang ◽  
Xin Chen ◽  
Wei-Yuan Zhou
Keyword(s):  
Damage Evolution ◽  
Evolution Laws

Chip Morphology Studies Using Separate Fracture Toughness Values for Chip Separation and Serration in Orthogonal Machining Simulations

2018 ◽  
Author(s):  
Jaimeen Patel ◽  
Harish P. Cherukuri
Keyword(s):  
Damage Evolution ◽  
Damage Model ◽  
Equivalent Plastic Strain ◽  
Chip Morphology ◽  
Threshold Value ◽  
Threshold Values ◽  
Orthogonal Machining ◽  
Evolution Laws ◽  
On Chip ◽  
Chip Separation

It is well known that the chip morphology predictions in machining simulations depend on the separation criteria used for modeling chip formation. In this paper, we propose to use two different criteria for chip separation and serration along with the Johnson-Cook damage model. The threshold value for chip separation is determined from machining experiments using the methodologies discussed in Patel et al. [1]. In addition, two separate damage evolution laws for chip separation and serration are used. Our results indicate that the choice of the evolution law and the threshold values of Gc used for chip separation and serration have a significant effect on chip shape and other field variables such as the equivalent plastic strain, cutting force, temperature, etc.

scholarly journals The Electrical Resistivity and Acoustic Emission Response Law and Damage Evolution of Limestone in Brazilian Split Test

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Xinji Xu ◽  
Bin Liu ◽  
Shucai Li ◽  
Jie Song ◽  
Ming Li ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Acoustic Emission ◽  
Damage Evolution ◽  
Bedding Plane ◽  
Damage Variable ◽  
Test Results ◽  
Loading Direction ◽  
Split Test ◽  
Evolution Laws ◽  
Loading Modes

The Brazilian split test was performed on two groups of limestone samples with loading directions vertical and parallel to the bedding plane, and the response laws of the electrical resistivity and acoustic emission (AE) in the two loading modes were obtained. The test results showed that the Brazilian split test with loading directions vertical and parallel to the bedding showed obviously different results and anisotropic characteristics. On the basis of the response laws of the electrical resistivity and AE, the damage variables based on the electrical resistivity and AE properties were modified, and the evolution laws of the damage variables in the Brazilian split test with different loading directions were obtained. It was found that the damage evolution laws varied with the loading direction. Specifically, in the time-varying curve of the damage variable with the loading direction vertical to the bedding, the damage variable based on electrical resistivity properties showed an obvious damage weakening stage while that based on AE properties showed an abrupt increase under low load.

Numerical integration of elasto-plasticity coupled to damage using a diagonal implicit Runge–Kutta integration scheme

2012 ◽  
Vol 22 (1) ◽  
pp. 68-94 ◽  
Author(s):  
Eric Borgqvist ◽  
Mathias Wallin
Keyword(s):  
Numerical Integration ◽  
Damage Evolution ◽  
Finite Strain ◽  
Integration Scheme ◽  
Euler Scheme ◽  
Implicit Euler Scheme ◽  
Damage Models ◽  
Integration Schemes ◽  
Evolution Laws ◽  
Runge Kutta

This article is concerned with the numerical integration of finite strain continuum damage models. The numerical sensitivity of two damage evolution laws and two numerical integration schemes are investigated. The two damage models differ in that one of the models includes a threshold such that the damage evolution is suppressed until a certain effective plastic strain is reached. The classical integration scheme based on the implicit Euler scheme is found to suffer from a severe step-length dependence. An alternative integration scheme based on a diagonal implicit Runge--Kutta scheme originally proposed by Ellsiepen ( 1999 ) is investigated. The diagonal implicit Runge--Kutta scheme is applied to the balance of momentum as well as the constitutive evolution equations. When applied to finite strain multiplicative plasticity, the diagonal implicit Runge--Kutta scheme destroys the plastic incompressibility of the underlying continuum evolution laws. Here, the evolution laws are modified such that the incompressibility of the plastic deformation is preserved approximately. The presented numerical examples reveal that a significant increase in accuracy can be obtained at virtually no cost using the diagonal implicit Runge--Kutta scheme. It is also shown that for the model including a discontinuous evolution law, the superiority of the diagonal implicit Runge--Kutta scheme over the implicit Euler scheme is reduced.

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