A framework for large strain elastic–plastic damage mechanics based on metric transformations

Starting from the thermodynamics, model of frozen soil is studied by energy dissipation theory and the inside and outside the state variables is given under isothermal conditions. Damage of frozen soil is re-flecked by effective stress and damage tensor in Damage Mechanics. Dissipation function is in form of plastic dissipation function (DP yield criterion) and the damage dissipation function. And plastic dissipation function is coupled of the damage variable. Through the elastic-plastic and damage evolution, frozen soil incremental elastic-plastic damage constitutive model is made. And finite element scheme is given.

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A Coupled Elastic-Plastic Damage Model for Rock Material

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.488-489.799 ◽

2014 ◽

Vol 488-489 ◽

pp. 799-802

Author(s):

Hong Jie Chen ◽

Wei Ya Xu ◽

Ru Bin Wang ◽

Wei Wang

Keyword(s):

Damage Mechanics ◽

Damage Model ◽

Confining Pressure ◽

Damage Mechanism ◽

Coupling Model ◽

Internal Variable ◽

Elastic Plastic ◽

Softening Behavior ◽

Plastic Damage ◽

Damage Constitutive Model

With complex mechanics character and under the action of compression and tension in tri-direction, rock will show coupled plastic-damage mechanism as its basic character. Phenomenological coupled elastic-plastic-damage constitutive model with internal variable is proposed based on thermal mechanics theory, elastic law and macro damage mechanics. Numerical experiments on this model and analyze the model character. The result shows that the coupling model could realize rocks softening behavior brought about by damage and strength enlargement caused by confining pressure increasing.

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A Practical Elastic Plastic Damage Model for Concrete

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.243-249.313 ◽

2011 ◽

Vol 243-249 ◽

pp. 313-318 ◽

Cited By ~ 3

Author(s):

Hu Qi ◽

Yun Gui Li ◽

Xi Lin Lu

Keyword(s):

Stress State ◽

Damage Mechanics ◽

Hydrostatic Stress ◽

Axial Stress ◽

Stress Component ◽

Damage Model ◽

Continuum Damage Mechanics ◽

Deviatoric Stress ◽

Elastic Plastic ◽

Plastic Damage

In this paper, an elastic plastic damage model is presented based on the combined use of elastic plastic constitutive equations along with continuum damage mechanics. A tensile and a compressive damage variable are adopted to describe the different responses of concrete under tension and compression, respectively. The Helmholtz Free Energy is decomposed into hydrostatic stress component and deviatoric stress components. The hydrostatic stress component is neglected and the deviatoric stress component is amended according to stress state, resulting in a more accurate description of the concrete’s response under multi-axial stress state. Finally, through several numerical simulations it is proved that the proposed model has the capability of simulating typical nonlinear performances of concrete material.

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Inelastic damage using continuum damage mechanics in composite plate reinforced by unidirectional fibers

MATEC Web of Conferences ◽

10.1051/matecconf/201815701023 ◽

2018 ◽

Vol 157 ◽

pp. 01023

Author(s):

Milan Žmindák ◽

Martin Dudinský

Keyword(s):

Composite Structures ◽

Composite Plate ◽

Damage Mechanics ◽

Continuum Damage Mechanics ◽

Continuum Damage ◽

Elastic Plastic ◽

Unidirectional Fibers ◽

Plastic Damage ◽

Inelastic Damage ◽

Matlab Programming

It is well that a finite element method is very popular simulation method to predict the physical behavior of systems and structures. In the last years an increase of interest in a new type of numerical methods known as meshless methods was observed. The paper deals with application of radial basis functions on modelling of inelastic damage using continuum damage mechanics of layered plate composite structures reinforced with long unidirectional fibers. For numerical simulations of elastic-plastic damage of layered composite plates own computational programs were implemented in MATLAB programming language. We will use the Newton-Raphson method to solve nonlinear systems of equations. Evaluation damage during plasticity has been solved using return mapping algorithm. The results of elastic-plastic damage analysis of composite plate with unsymmetrical laminate stacking sequence are presented.

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Elastic-Plastic Fractal Damage Constitutive Law for Concrete

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.382.348 ◽

2011 ◽

Vol 382 ◽

pp. 348-351

Author(s):

Ming Xie ◽

Shan Suo Zheng

Keyword(s):

Damage Mechanics ◽

Crack Surface ◽

Constitutive Law ◽

Test Results ◽

Uniaxial Test ◽

Elastic Plastic ◽

Mechanics Model ◽

Plastic Damage ◽

Evolution Characteristics ◽

Mesoscopic Level

In consideration of stochastik and discreteness of fracture surface, a class of mesoscopic damage mechanics model of concrete based on spring model, are put forward to understand the real damage evolution characteristics of concrete at the level of constitutional law. A kind of spring-slipper model is introduced to reflect the elastic-plastic damage behavior. Uniaxial test was operated, combined with the Computerized Tomography test of concrete, to study the evolution of crack surface from mesoscopic level to macroscopic level. And the rationality of fractal damage constitutive law was verified with their theoretical calculation result and test results. Compared with the existing damage constitutive law and experimental results preliminarily, the feasibility of fractal damage constitutive law is verified.

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Three-dimensional elastic-plastic damage constitutive model of wood

Holzforschung ◽

10.1515/hf-2019-0247 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Lipeng Zhang ◽

Qifang Xie ◽

Baozhuang Zhang ◽

Long Wang ◽

Jitao Yao

Keyword(s):

Constitutive Model ◽

Damage Mechanics ◽

Euler Method ◽

Isotropic Hardening ◽

Damage Initiation ◽

Elastic Plastic ◽

Plastic Damage ◽

Backward Euler ◽

Tension And Compression ◽

Damage Constitutive Model

AbstractA 3D combined elastic-plastic damage constitutive model for wood is proposed within the theoretical framework of classical plasticity and continuum damage mechanics (CDM). The model is able to describe the various behavior of wood under loading, including the orthotropic elasticity, strengths inequality under tension and compression in each orthotropic direction, ductile softening under longitudinal compression, brittle failure under transverse tension, and parallel shearing, densification hardening under transverse compression. Hoffman criterion and a set of eight separate failure criteria were used to define wood yielding and damage initiation, respectively. Isotropic hardening was assumed after yielding and defined by an exponential type function. The constitutive model was implicitly discretized using backward Euler method, solved through the return mapping algorithm and implemented into ABAQUS through the user-defined material subroutine (UMAT). The proposed model was firstly verified by material property tests considering different stress states: monotonic and repeated tension and compression (in both parallel and perpendicular-to-grain directions), parallel-to-grain shearing, and the interactions between perpendicular-to-grain compression/tension and parallel-to-grain shearing, etc. Mechanical behavior of typical structural elements was further simulated to validate the proposed constitutive model.

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Studying the effect of a hydrostatic stress/strain reduction factor on damage mechanics of concrete materials

Journal of the Mechanical Behavior of Materials ◽

10.1515/jmbm-2013-0022 ◽

2013 ◽

Vol 22 (5-6) ◽

pp. 149-159

Author(s):

Ziad N. Taqieddin ◽

George Z. Voyiadjis

Keyword(s):

Damage Mechanics ◽

Internal State ◽

Hydrostatic Stress ◽

Damage Model ◽

Reduction Factor ◽

State Variables ◽

Elastic Plastic ◽

Damage Models ◽

Plastic Damage ◽

Concrete Materials

AbstractIn the non-linear finite element analysis (NFEA) of concrete materials, continuum damage mechanics (CDM) provides a powerful framework for the derivation of constitutive models capable of describing the mechanical behavior of such materials. The internal state variables of CDM can be introduced to the elastic analysis of concrete to form elastic-damage models (no inelastic strains), or to the elastic-plastic analysis in order to form coupled/uncoupled elastic-plastic-damage models. Experimental evidence that is well documented in literature shows that the susceptibility of concrete to damage and failure is distinguished under deviatoric loading from that corresponding to hydrostatic loading. A reduction factor is usually introduced into a CDM model to reduce the susceptibility of concrete to hydrostatic stresses/strains. In this work, the effect of a hydrostatic stress/strain reduction factor on the performances of two NFEA concrete models will be studied. These two (independently published) models did not provide any results showing such effect. One of these two models is an elastic-damage model, whereas the other is an uncoupled elastic-plastic-damage model. Simulations and comparisons are carried out between the performances of the two models under uniaxial tensile and compressive loading conditions. Simulations are also provided for the uncoupled elastic-plastic-damage model under the following additional loading conditions: biaxial tension and biaxial compression, uniaxial cyclic loading, and varying ratios of triaxial compressive loadings. These simulations clearly show the effect of the reduction factor on the numerically depicted behaviors of concrete materials. To have rational comparisons, the hydrostatic stress reduction factor applied to each model is chosen to be a function of the internal state variables common to both models. Therefore, once the two models are calibrated to simulate the experimental behaviors, their corresponding reduction factors are readily available at every increment of the iterative NFEA procedures.

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