scholarly journals A Coupled Plastic Damage Model for Concrete considering the Effect of Damage on Plastic Flow

2015 ◽  
Vol 2015 ◽  
pp. 1-13
Author(s):  
Feng Zhou ◽  
Guangxu Cheng
Keyword(s):  
Damage Model ◽  
Compressive Loading ◽  
Plain Concrete ◽  
Yield Function ◽  
Reduction Factor ◽  
Loading History ◽  
Plastic Yield ◽  
Plastic Damage ◽  
Compliance Tensor ◽  
Proposed Model

A coupled plastic damage model with two damage scalars is proposed to describe the nonlinear features of concrete. The constitutive formulations are developed by assuming that damage can be represented effectively in the material compliance tensor. Damage evolution law and plastic damage coupling are described using the framework of irreversible thermodynamics. The plasticity part is developed without using the effective stress concept. A plastic yield function based on the true stress is adopted with two hardening functions, one for tensile loading history and the other for compressive loading history. To couple the damage to the plasticity, the damage parameters are introduced into the plastic yield function by considering a reduction of the plastic hardening rate. The specific reduction factor is then deduced from the compliance tensor of the damaged material. Finally, the proposed model is applied to plain concrete. Comparison between the experimental data and the numerical simulations shows that the proposed model is able to describe the main features of the mechanical performances observed in concrete material under uniaxial, biaxial, and cyclic loadings.

A coupled elastoplastic anisotropic damage model for rock materials

2020 ◽  
Vol 29 (8) ◽  
pp. 1222-1245
Author(s):  
Susheng Wang ◽  
Weiya Xu
Keyword(s):  
Coupling Effect ◽  
Damage Model ◽  
Coupled Model ◽  
Yield Function ◽  
Anisotropic Damage ◽  
Mapping Algorithm ◽  
Rock Materials ◽  
Return Mapping ◽  
Brittle Ductile Transition ◽  
Proposed Model

In this study, a rigorous constitutive model within the framework of thermodynamics is formulated to describe the coupling process between irreversible deformation and anisotropic damage of rock materials. The coupling effect is reflected based on the “two-surface” formulation. The plastic response is described by a yield function while the anisotropic damage is defined by a novel exponential damage criterion. In the proposed model, another feature lies in introducing parameters β and k in the proposed model to capture strain hardening/softening behaviors and brittle–ductile transition. The computational formulation scheme for the coupled model is deduced in detail by using return mapping algorithm. The validity of the coupled model is compared with the numerical simulation results and the experimental curves of the fine-grained sandstone, Beishan granite, and Jinping marble. The results indicate that the model can take into account the nonlinear mechanical behaviors of rock: coupling anisotropic damage and plasticity as well as brittle-ductile transition behaviors. Without loss of generality, the coupled model is versatile to describe the mechanical characteristics of rock materials.

Un modèle thermo-plastique couplé à l'endommagement pour le béton à hautes températures

2001 ◽  
Vol 28 (4) ◽  
pp. 593-607 ◽  
Author(s):  
Wahid Nechnech ◽  
Jean-Marie Reynouard ◽  
Fekri Meftah
Keyword(s):  
Damage Mechanics ◽  
Constitutive Relations ◽  
Damage Model ◽  
Thermal Action ◽  
Plain Concrete ◽  
Continuum Damage Mechanics ◽  
Mechanical Action ◽  
Proposed Model ◽  
Damage Theory ◽  
And Performance

In this paper a new thermoplastic damage model for plain concrete subjected to combined thermal and cyclic loading is developed using the concept of plastic-work hardening and stiffness degradation in continuum damage mechanics. Two damage variables are used: one for mechanical action and the other one for thermal action. Further, thermomechanical interaction strains have been introduced to describe the influence of mechanical loading on the physical process of thermal expansion of concrete. The constitutive relations for elastoplastic responses are decoupled from the degradation damage responses by using the effective stress concept. This method provides advantages in the numerical implementation. Efficient computational algorithms for the proposed model are subsequently explored and performance of this model is demonstrated with numerical examples.Key words: damage theory, plasticity, thermal, unilateral phenomenon, thermomechanical interaction.

scholarly journals Modelling of High Velocity Impact on Concrete Structures Using a Rate-Dependent Plastic-Damage Microplane Approach at Finite Strains

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5165
Author(s):  
Bobby Rio Indriyantho ◽  
Imadeddin Zreid ◽  
Robert Fleischhauer ◽  
Michael Kaliske
Keyword(s):  
Yield Function ◽  
Nonlinear Behaviour ◽  
Rate Dependency ◽  
Microplane Model ◽  
Rate Dependent ◽  
Plastic Damage ◽  
Proposed Model ◽  
Concrete Materials ◽  
Element Erosion ◽  
Gradient Enhancement

Concrete is known as a quasi-brittle material and the microplane model has been proven to be a powerful method to describe its constitutive features. For some dynamic cases, however, numerous microplane models used successfully at small strains are not sufficient to predict the nonlinear behaviour of damaged concrete due to large deformations. In this contribution at hand, a combined plasticity-damage microplane model extended to the finite strain framework is formulated and regularised using implicit gradient enhancement to achieve mesh insensitivity and to obtain more stable finite element solutions. A modified smooth three surface Drucker–Prager yield function with caps is introduced within the compression-tension split. Moreover, a viscoplastic consistency formulation is implemented to deliver rate dependency at dynamic cases. In case of penetration into concrete materials, the proposed model is equipped with an element erosion procedure to yield a better approximation of crack patterns. Numerical examples on impact cases are performed to challenge the capability of the newly proposed model to existing experimental data.

Elasticity Damage and Plastic Analyses of Masonry

2012 ◽  
Vol 166-169 ◽  
pp. 1454-1458 ◽  
Author(s):  
Wen Fang Zhang ◽  
Huan Wang
Keyword(s):  
Plastic Strain ◽  
Damage Model ◽  
Compressive Loading ◽  
Shear Loading ◽  
Stress And Strain ◽  
Irreversible Damage ◽  
Elastic Module ◽  
Plastic Damage ◽  
Masonry Material ◽  
Elastic Stage

The relation between stress and strain of masonry material under uniaxial monotonic condition is analyzed and the initial elastic stage is proposed for elastoplastic analyses. Furthermore, plastic damage model and elastic module degradation with plastic strain are investigated. The model describes the effects of irreversible damage: elastic module is fully determined by accumulated plastic strain; compressive stiffness may be recovered during cyclic loading. Based on the model, elastic module degradation and incremental stress-strain equations under multiaxial loading are discussed. Finally masonry shearwall under invariable compressive loading and monotonic shear loading is calculated, and plastic tensional strain before crushing is shown.

A Computational Model for Fe Ductile Plastic Damage Analysis of Plate Bending

1993 ◽  
Vol 60 (3) ◽  
pp. 749-758 ◽  
Author(s):  
Guangyu Shi ◽  
G. Z. Voyiadjis
Keyword(s):  
Computational Model ◽  
Stiffness Matrix ◽  
Damage Model ◽  
Strain Energy Release ◽  
Elastic Stiffness ◽  
Yield Function ◽  
Damage Effect ◽  
Damage Analysis ◽  
Plastic Damage ◽  
Elastoplastic Damage

This paper presents a computational model for the finite element plastic damage analysis of ductile flexural plates. The phenomenological damage model proposed by Lemaitre is adopted here. The damage effect parameters of a cross-section are defined and employed to account for the damage effect across the thickness of a bending plate. Similar to the effective stresses used in many damage models, the effective stress couples are introduced in this work and used in the yield function. The damage criterion is defined in terms of damage strain energy release rates. Based on the damage node model proposed here, the elastoplastic-damage stiffness matrix of element is derived. When the corresponding elastic stiffness matrix is given explicitly, the resulting elastoplastic-damage stiffness matrix can be evaluated without use of numerical integration. The feature of the expicit form of element stiffness matrix makes the computational model proposed here very efficient. Several numerical examples of ductile plastic damage analysis of plates are also given in this work to demonstrate the validity of the computational model.

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

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.

An elasto-plastic damage model for plain concrete subjected to high temperatures

2002 ◽  
Vol 24 (5) ◽  
pp. 597-611 ◽  
Author(s):  
W. Nechnech ◽  
F. Meftah ◽  
J.M. Reynouard
Keyword(s):  
High Temperatures ◽  
Damage Model ◽  
Plain Concrete ◽  
Plastic Damage

Nonlinear Analysis of Two Shear Walls Using Elastic Plastic Damage Model

2012 ◽  
Vol 182-183 ◽  
pp. 1581-1584
Author(s):  
Lin Lin ◽  
Cheng He Li ◽  
Hu Qi
Keyword(s):  
Static Loading ◽  
Damage Model ◽  
Shear Walls ◽  
Shear Wall ◽  
Damage Distribution ◽  
Elastic Plastic ◽  
Concrete Members ◽  
Plastic Damage ◽  
Proposed Model ◽  
Simulation Results

In this paper, the elastic plastic damage model for concrete under static loading previously proposed by Hu Qi et al. is developed in ABAQUS via UMAT, and it is verified by the simulation of two shear wall members under horizontal loading. The simulation results indicate that this constitutive model can accurately predict typical nonlinear performances of reinforcement concrete shear walls. Using the proposed model one can get the damage distribution of reinforced concrete members which is helpful for researchers to get the failure pattern of structures.

A Dynamic Three Invariant Cap-Viscoplastic Damage Model for Ultrahigh-Performance Concrete

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Bhasker Paliwal ◽  
Youssef Hammi ◽  
Mei Chandler ◽  
Robert D. Moser ◽  
Mark F. Horstemeyer
Keyword(s):  
Damage Model ◽  
Compressive Loading ◽  
Dynamic Strain ◽  
Army Corps ◽  
Army Corps Of Engineers ◽  
Damage Initiation ◽  
Rate Dependent ◽  
Proposed Model ◽  
Damage Constitutive Model ◽  
Reactive Powder

A new dynamic strain rate-dependent elasto-viscoplastic damage constitutive model for ultrahigh-performance concrete (UHPC) is developed by incorporating Duvaut–Lions viscoplasticity generalized to multisurface plasticity followed by rate-dependent dynamic damage initiation and evolution under multiaxial loading, to our previous elastoplastic damage model. The predictive capability of the proposed model is compared against experimental results and experimentally observed features from tests on Cor-Tuf concrete, a reactive powder concrete (RPC) and a proprietary UHPC developed by the U.S. Army Corps of Engineers. These experiments were conducted under various compressive loading conditions under low to high confinement and different strain rates, and model predictions demonstrate excellent agreement with these results.

A novel non-linear cumulative fatigue damage model based on the degradation of material memory

2019 ◽  
Vol 29 (4) ◽  
pp. 610-625
Author(s):  
Jie Zhou ◽  
Hong-Zhong Huang ◽  
Miles V Barnhart ◽  
Guoliang Huang ◽  
Yan-Feng Li
Keyword(s):  
Experimental Data ◽  
Fatigue Damage ◽  
Residual Life ◽  
Damage Model ◽  
Loading History ◽  
Material Parameters ◽  
Life Estimation ◽  
Damage Models ◽  
Proposed Model ◽  
Cumulative Fatigue Damage

Many fatigue damage models have been investigated based on the S– N curve or modified S– N curve; however, a number of them require additional efforts to determine the material parameters or do not consider the loading history (loading interactions, loading sequences, loading levels, etc.). These limitations can result in extreme deviations for estimating the fatigue life in real-world scenarios. To address these limitations, a new fatigue damage model is developed based on the material memory, which can be described as the degradation of mechanical properties under cyclic loadings. Comparisons with three models are used to demonstrate the validity of the proposed model. Furthermore, four sets of experimental data under two-stress and four-stress levels are carried out to verify the validation of the proposed model, which improves the residual life estimation over the three existing models used for comparison.

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