scholarly journals Numerical Implementation of Spatial Elastoplastic Damage Model of Concrete in the Framework of Isogeometric Analysis Approach

2016 ◽  
Vol 2016 ◽  
pp. 1-13
Author(s):  
Cheng Ma ◽  
Wei-zhen Chen ◽  
Jian-yuan Sun
Keyword(s):  
Isogeometric Analysis ◽  
Geometric Modeling ◽  
Damage Model ◽  
Internal Variables ◽  
Flow Rule ◽  
Equilibrium Path ◽  
Numerical Implementation ◽  
Mapping Algorithm ◽  
Solution Algorithms ◽  
Elastoplastic Damage

This paper is a study of the numerical implementation of the spatial elastoplastic damage model of concrete by isogeometric analysis (IGA) method from three perspectives: the geometric modeling and the numerical formulation via IGA method, the constitutive model of concrete, and the solution algorithms for the local and global problems. The plasticity of concrete is considered on the basis of a nonassociated flow rule, where a three-parameter Barcelona yield surface and a modified Drucker-Prager plastic potential are used. The damage evolution of concrete driven by the internal variables is expressed by a piecewise function. In the study, the return-mapping algorithm and the substepping strategy are used for stress updating, and a new dissipation-based arc-length method with constraint path that considers the combined contribution of plasticity and damage to the energy dissipation is employed to trace the equilibrium path. After comparisons between simulation results and experimental data, the use of the elastoplastic damage model in the framework of IGA approach is proven to be practical in reflecting material properties of concrete.

Three-dimensional elastoplastic damage concrete model by dissipation-based arc-length method

2016 ◽  
Vol 19 (12) ◽  
pp. 1949-1962
Author(s):  
Cheng Ma ◽  
Wei-zhen Chen
Keyword(s):  
Damage Model ◽  
Three Dimensional ◽  
Iterative Solution ◽  
Yield Function ◽  
Flow Rule ◽  
Arc Length ◽  
Mapping Algorithm ◽  
Return Mapping ◽  
Operator Split ◽  
Elastoplastic Damage

This article presents a three-dimensional isotropic elastoplastic damage model for concrete structures. The plasticity of concrete is described by a nonassociated flow rule, using a three-parameter yield function as well as a modified Drucker–Prager-type potential. The damage of concrete is seen as a contribution work of tensile and compressive damage, with the evolution histories driven by the internal tensile and compressive variables, respectively. The iterative solution of plasticity and damage is carried out according to the concept of operator split, where a return-mapping algorithm as well as a substepping strategy is used. The consistent tangent stiffness considering the recursive relationship among substeps is derived. For the solution of global iteration, a dissipation-based arc-length method is employed. Good agreements are found in comparisons between numerical results and experimental data on both elementary and structural levels. Furthermore, the sensitivities of parameters that control strain softening are investigated.

scholarly journals A Coupled Elastoplastic Damage Model for Clayey Rock and Its Numerical Implementation and Validation

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Shanpo Jia ◽  
Zhenyun Zhao ◽  
Guojun Wu ◽  
Bisheng Wu ◽  
Caoxuan Wen
Keyword(s):  
Damage Model ◽  
Clayey Rock ◽  
Triaxial Tests ◽  
Numerical Implementation ◽  
Integration Algorithm ◽  
Stress Criterion ◽  
Proposed Model ◽  
Maximal Tensile Stress ◽  
Nonlinear Hardening ◽  
Elastoplastic Damage

This paper presents a new constitutive model for describing the strain-hardening and strain-softening behaviors of clayey rock. As the conventional Mohr-Coulomb (CMC) criterion has its limitation in the tensile shear region, a modified Mohr-Coulomb (MMC) criterion is proposed for clayey rock by considering the maximal tensile stress criterion. Based on the results of triaxial tests, a coupled elastoplastic damage (EPD) model, in which the elastic and plastic damage laws are introduced to describe the nonlinear hardening and softening behaviors, respectively, is developed so as to fully describe the mechanical behavior of clayey rock. Starting from the implicit Euler integration algorithm, the stress-strain constitutive relationships and their numerical formulations are deduced for finite element implementation in the commercial package ABAQUS where a user-defined material subroutine (UMAT) is provided for clayey rock. Finally, the proposed model is used to simulate the triaxial tests and the results validate the proposed model and numerical implementation.

A thermodynamic consistent rate-dependent elastoplastic-damage model

2016 ◽  
Vol 27 (3) ◽  
pp. 333-356 ◽  
Author(s):  
Mehdi Ganjiani
Keyword(s):  
Constitutive Model ◽  
Strain Rate ◽  
Damage Mechanics ◽  
Effective Strain ◽  
Damage Model ◽  
Dissipation Function ◽  
Internal Variables ◽  
Finite Element Program ◽  
Rate Dependent ◽  
Elastoplastic Damage

In this article, a rate-dependent elastoplastic-damage constitutive model considering the effect of strain rate has been developed. The derivation of this model has been established based on the irreversible thermodynamics with internal variables within the fundamentals of Continuum damage mechanics (CDM). For investigating the rate effect, an additional power function dependent on the effective strain rate has been involved in the plastic dissipation function (dynamic plastic yield surface). The damage has been assumed as a tensor-type variable and based on the energy equivalence hypothesis, the damage evolution has been developed. The proposed constitutive model has been implemented into user-defined subroutines UMAT and VUMAT in the finite-element program ABAQUS/(Standard and Explicit). For this purpose, the implicit and explicit stress integration algorithms of the model have been explained. The model has been validated by comparing the predicted results with experimental data conducted on Al2024-T3. These experiments are including the tensile and double-notched tests. Furthermore, the numerical results have been compared with some data available in the literature. The numerical examples show the excellent correlation between experiments and simulations for stress (or force) and damage results.

scholarly journals Development of Elastoplastic-Damage Model of AlFeSi Phase for Aluminum Alloy 6061

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 954
Author(s):  
Hailong Wang ◽  
Wenping Deng ◽  
Tao Zhang ◽  
Jianhua Yao ◽  
Sujuan Wang
Keyword(s):  
Aluminum Alloy ◽  
Constitutive Model ◽  
Material Properties ◽  
Damage Model ◽  
Scratch Test ◽  
Aluminum Alloy 6061 ◽  
Ultra Precision ◽  
Simulation Results ◽  
Alloy 6061 ◽  
Elastoplastic Damage

Material properties affect the surface finishing in ultra-precision diamond cutting (UPDC), especially for aluminum alloy 6061 (Al6061) in which the cutting-induced temperature rise generates different types of precipitates on the machined surface. The precipitates generation not only changes the material properties but also induces imperfections on the generated surface, therefore increasing surface roughness for Al6061 in UPDC. To investigate precipitate effect so as to make a more precise control for the surface quality of the diamond turned Al6061, it is necessary to confirm the compositions and material properties of the precipitates. Previous studies have indicated that the major precipitate that induces scratch marks on the diamond turned Al6061 is an AlFeSi phase with the composition of Al86.1Fe8.3Si5.6. Therefore, in this paper, to study the material properties of the AlFeSi phase and its influences on ultra-precision machining of Al6061, an elastoplastic-damage model is proposed to build an elastoplastic constitutive model and a damage failure constitutive model of Al86.1Fe8.3Si5.6. By integrating finite element (FE) simulation and JMatPro, an efficient method is proposed to confirm the physical and thermophysical properties, temperature-phase transition characteristics, as well as the stress–strain curves of Al86.1Fe8.3Si5.6. Based on the developed elastoplastic-damage parameters of Al86.1Fe8.3Si5.6, FE simulations of the scratch test for Al86.1Fe8.3Si5.6 are conducted to verify the developed elastoplastic-damage model. Al86.1Fe8.3Si5.6 is prepared and scratch test experiments are carried out to compare with the simulation results, which indicated that, the simulation results agree well with those from scratch tests and the deviation of the scratch force in X-axis direction is less than 6.5%.

Parameterization, Geometric Modeling, and Isogeometric Analysis for Tricuspid Valve Applications

2021 ◽  
Author(s):  
Emily L. Johnson ◽  
Devin Laurence ◽  
Caroline E. Crisp ◽  
Chung-Hao Lee ◽  
Ming-Chen Hsu
Keyword(s):  
Tricuspid Valve ◽  
Isogeometric Analysis ◽  
Geometric Modeling

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.

scholarly journals A New 3D Empirical Plastic and Damage Model for Simulating the Failure of Concrete Structure

2019 ◽  
Vol 13 (1) ◽  
Author(s):  
Yan-tao Jiao ◽  
Bo Wang ◽  
Zhen-zhong Shen
Keyword(s):  
Damage Mechanics ◽  
Evolution Equations ◽  
Influence Factor ◽  
Yield Criterion ◽  
Kinematic Hardening ◽  
Damage Model ◽  
Nonlinear Behavior ◽  
Complex Stress State ◽  
Flow Rule ◽  
Wide Range

Abstract A new plastic–damage constitutive model based on the combination of damage mechanics and classical plastic theory was developed to simulate the failure of concrete. In order to explain different material behaviors of concrete under tensile and compressive loadings, the plastic yield criterion, the different kinematic hardening rule for tension and compressive and the isotropic flow rule were established in the effective stress space. Meanwhile, two different empirical damage evolution equations were adopted: one for compression and the other for tension. A multi-axial damage influence factor was also introduced to fully describe the anisotropic damage of concrete. Finally, the model response was compared with a wide range of experiment results. The results showed that the model could well describe the nonlinear behavior of concrete in a complex stress state.

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