Study on Nonlinear Behavior of Human Hard Tissue Based On Isotropic Damage Model

Abstract In this paper, the probabilistic behavior of plain concrete beams subjected to flexure is studied using a continuous mesoscale model. The model is two-dimensional where aggregate and mortar are treated as separate constituents having their own characteristic properties. The aggregate is represented as ellipses and generated under prescribed grading curves. Ellipses are randomly placed so it requires probabilistic analysis for model using the Monte Carlo simulation with 20 realizations to represent geometry uncertainty. The nonlinear behavior is simulated with an isotropic damage model for the mortar, while the aggregate is assumed to be elastic. The isotropic damage model softening behavior is defined in terms of fracture mechanics parameters. This damage model is compared with the fixed crack model in macroscale study before using it in the mesoscale model. Then, it is used in the mesoscale model to simulate flexure test and compared to experimental data and shows a good agreement. The probabilistic behavior of the model response is presented through the standard deviation, moment parameters and cumulative probability density functions in different loading stages. It shows variation of the probabilistic characteristics between pre-peak and post-peak behaviour of load-CMOD curves.

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Isotropic damage model and serial/parallel mix theory applied to nonlinear analysis of ferrocement thin walls. Experimental and numerical analysis

Ingeniería e Investigación ◽

10.15446/ing.investig.v36n1.52810 ◽

2016 ◽

Vol 36 (1) ◽

pp. 41-51

Author(s):

Jairo A. Paredes ◽

Daniel Alveiro Bedoya-Ruiz ◽

Jorge E. Hurtado Gómez

Keyword(s):

Numerical Analysis ◽

Static Loading ◽

Structural Parameters ◽

Damage Model ◽

Nonlinear Behavior ◽

Loading Conditions ◽

Thin Walls ◽

Earthquake Resistant Design ◽

Earthquake Resistant ◽

Isotropic Damage

<p>Ferrocement thin walls are the structural elements that comprise the earthquake resistant system of dwellings built with this material. This article presents the results drawn from an experimental campaign carried out over full-scale precast ferrocement thin walls that were assessed under lateral static loading conditions. The tests allowed the identification of structural parameters and the evaluation of the performance of the walls under static loading conditions. Additionally, an isotropic damage model for modelling the mortar was applied, as well as the classic elasto-plastic theory for modelling the meshes and reinforcing bars. The ferrocement is considered as a composite material, thus the serial/parallel mix theory is used for modelling its mechanical behavior. In this work a methodology for the numerical analysis that allows modeling the nonlinear behavior exhibited by ferrocement walls under static loading conditions, as well as their potential use in earthquake resistant design, is proposed.</p>

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A multiscale elasto-plastic damage model for the nonlinear behavior of 3D braided composites

Composites Science and Technology ◽

10.1016/j.compscitech.2018.12.003 ◽

2019 ◽

Vol 171 ◽

pp. 21-33 ◽

Cited By ~ 27

Author(s):

Chunwang He ◽

Jingran Ge ◽

Dexing Qi ◽

Jiaying Gao ◽

Yanfei Chen ◽

...

Keyword(s):

Damage Model ◽

Nonlinear Behavior ◽

Braided Composites ◽

3D Braided Composites ◽

Plastic Damage

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Failure Predictions for DP Steel Cross-die Test using Anisotropic Damage

International Journal of Damage Mechanics ◽

10.1177/1056789511407646 ◽

2011 ◽

Vol 21 (5) ◽

pp. 713-754 ◽

Cited By ~ 18

Author(s):

M. S. Niazi ◽

H. H. Wisselink ◽

T. Meinders ◽

J. Huétink

Keyword(s):

Strain Rate ◽

Damage Evolution ◽

Damage Model ◽

Anisotropic Damage ◽

Continuum Damage ◽

Anisotropic Plasticity ◽

Continuum Damage Model ◽

Damage Models ◽

Isotropic Damage ◽

Failure Predictions

The Lemaitre's continuum damage model is well known in the field of damage mechanics. The anisotropic damage model given by Lemaitre is relatively simple, applicable to nonproportional loads and uses only four damage parameters. The hypothesis of strain equivalence is used to map the effective stress to the nominal stress. Both the isotropic and anisotropic damage models from Lemaitre are implemented in an in-house implicit finite element code. The damage model is coupled with an elasto-plastic material model using anisotropic plasticity (Hill-48 yield criterion) and strain-rate dependent isotropic hardening. The Lemaitre continuum damage model is based on the small strain assumption; therefore, the model is implemented in an incremental co-rotational framework to make it applicable for large strains. The damage dissipation potential was slightly adapted to incorporate a different damage evolution behavior under compression and tension. A tensile test and a low-cycle fatigue test were used to determine the damage parameters. The damage evolution was modified to incorporate strain rate sensitivity by making two of the damage parameters a function of strain rate. The model is applied to predict failure in a cross-die deep drawing process, which is well known for having a wide variety of strains and strain path changes. The failure predictions obtained from the anisotropic damage models are in good agreement with the experimental results, whereas the predictions obtained from the isotropic damage model are slightly conservative. The anisotropic damage model predicts the crack direction more accurately compared to the predictions based on principal stress directions using the isotropic damage model. The set of damage parameters, determined in a uniaxial condition, gives a good failure prediction under other triaxiality conditions.

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Fracture simulations using edge-based smoothed finite element method for isotropic damage model via Delaunay/Voronoi dual tessellations

International Journal of Damage Mechanics ◽

10.1177/10567895211040549 ◽

2021 ◽

pp. 105678952110405

Author(s):

Young Kwang Hwang ◽

Suyeong Jin ◽

Jung-Wuk Hong

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Voronoi Tessellation ◽

Damage Model ◽

Time Integration ◽

Voronoi Cell ◽

Smoothed Finite Element Method ◽

Isotropic Damage ◽

Edge Based ◽

Element Method

In this study, an effective numerical framework for fracture simulations is proposed using the edge-based smoothed finite element method (ES-FEM) and isotropic damage model. The duality between the Delaunay triangulation and Voronoi tessellation is utilized for the mesh construction and the compatible use of the finite element solution with the Voronoi-cell lattice geometry. The mesh irregularity is introduced to avoid calculating the biased crack path by adding random variation in the nodal coordinates, and the ES-FEM elements are defined along the Delaunay edges. With the Voronoi tessellation, each nodal mass is calculated and the fractured surfaces are visualized along the Voronoi edges. The rotational degrees of freedom are implemented for each node by introducing the elemental formulation of the Voronoi-cell lattice model, and the accurate visualizations of the rotational motions in the Voronoi diagram are achieved. An isotropic damage model is newly incorporated into the ES-FEM formulation, and the equivalent elemental length is introduced with an additional geometric factor to simulate the consistent softening behaviors with reducing the mesh sensitivity. The full matrix form of the smoothed strain-displacement matrix is constructed for optimal use in the element-wise computations during explicit time integration, and parallel computing is implemented for the enhancement of the computational efficiency. The simulated results are compared with the theoretical solutions or experimental results, which demonstrates the effectiveness of the proposed methodology in the simulations of the quasi-brittle fractures.

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Lifetime Prediction of Rocket Combustion Chamber Wall by Means of Viscoplasticity Coupled With Ductile Isotropic Damage

Volume 1: Advanced Computational Mechanics; Advanced Simulation-Based Engineering Sciences; Virtual and Augmented Reality; Applied Solid Mechanics and Material Processing; Dynamical Systems and Control ◽

10.1115/esda2012-82748 ◽

2012 ◽

Cited By ~ 2

Author(s):

Vivian Tini ◽

Ivaylo N. Vladimirov ◽

Stefanie Reese

Keyword(s):

Combustion Chamber ◽

Copper Alloy ◽

Kinematic Hardening ◽

Damage Model ◽

Chamber Wall ◽

Lifetime Prediction ◽

Viscoplastic Model ◽

Material Parameters ◽

Isotropic Damage ◽

Wall Materials

This paper presents the application of a viscoplastic damage model for the lifetime prediction of a typical rocket combustion chamber structure. The material modeling is motivated by extension of the classical rheological model for elastoplasticity with Armstrong-Frederick kinematic hardening into a viscoplastic model. The coupling with damage is performed using the concept of effective stress and the principle of strain equivalence. The material parameters are identified based on experimental results for the high temperature copper alloy NARloy-Z, which is one of the typical combustion chamber wall materials. Finally the applicability of the model will be shown by means of sequentially coupled thermomechanical analyses.

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A Spectral Microplane Model for the Anisotropic Damage Behavior of Shales

Journal of Applied Mechanics ◽

10.1115/1.4047005 ◽

2020 ◽

Vol 87 (8) ◽

Author(s):

Mingyao Li ◽

Xin Chen ◽

Dong Zhou ◽

Yewang Su

Keyword(s):

Damage Model ◽

Constitutive Models ◽

Nonlinear Behavior ◽

Bedding Plane ◽

Anisotropic Elasticity ◽

Anisotropic Damage ◽

Microplane Model ◽

Damage Behavior ◽

Softening Behavior ◽

Confining Pressures

Abstract The development of constitutive models for shales has been a challenge for decades due to the difficulty of characterizing the strongly anisotropic macroscopic behavior related to the inherent mesostructure and damage mechanisms. In this paper, a spectral microplane damage model is developed for the anisotropic damage behavior of shales. The modeling challenge of the anisotropic elasticity in the microplane model is theoretically overcome by the spectral decomposition theory without limitation on the degree of the anisotropy compared with other microplane models. The stiffness tensor of anisotropic shales is effectively decomposed into four different eigenmodes with the activation of certain groups of microplanes corresponding to the specific orientation of the applied stresses. The inherent and the induced anisotropic behavior is thus characterized by proposing suitable microplane relations on certain eigenmodes directly reflecting the initial mesostructure and the failure mechanisms. For the challenge of the postpeak softening behavior, two-scalar damage variables are introduced to characterize the tensile and the shear damage related to the opening and the closure of microcracks under different stress conditions. Comparison between numerical simulation and experimental data shows that the proposed model provides satisfactory predictions for both weakly and highly anisotropic shales including prepeak nonlinear behavior, failure strengths, and postpeak softening under different confining pressures and different bedding plane orientations.

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

International Journal of Concrete Structures and Materials ◽

10.1186/s40069-019-0362-z ◽

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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Cyclic Loading of Beams Based on Kinematics Hardening Behavior Coupled With Isotropic Damage

Volume 4: Fatigue and Fracture, Heat Transfer, Internal Combustion Engines, Manufacturing, and Technology and Society ◽

10.1115/esda2006-95239 ◽

2006 ◽

Cited By ~ 1

Author(s):

Ali Nayebi ◽

Kourosh H. Shirazi

Keyword(s):

Cyclic Loading ◽

Strain Hardening ◽

Kinematic Hardening ◽

Damage Model ◽

Mapping Algorithm ◽

Return Mapping ◽

Tension And Compression ◽

Computational Aspects ◽

Isotropic Damage ◽

Path Dependent

The kinematic hardening theory of plasticity based on the Prager model and incremental isotropic damage is used to evaluate the cyclic loading behavior of a beam under the axial, bending, and thermal loads. This allows damage to be path-dependent. The damage and inelastic deformation are incorporated and they are used for the analysis of the beam. The beam material is assumed to follow linear strain hardening property coupled with isotropic damage. The material strain hardening curves in tension and compression are assumed to be both identical for the isotropic material. Computational aspects of rate independent model is discussed and the constitutive equation of the rate independent plasticity coupled with the damage model are decomposed into the elastic, plastic and damage parts. Return Mapping Algorithm method is used for the correction of the elastoplastic state and for the damage model the algorithm is used according to the governed damage constitutive relation. The effect of the damage phenomenon coupled with the elastoplastic kinematic hardening is studied for deformation and load control loadings.

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A Multi-Level Superelement Technique for Damage Analysis

Materials: Processing, Characterization and Modeling of Novel Nano-Engineered and Surface Engineered Materials ◽

10.1115/imece2002-39190 ◽

2002 ◽

Author(s):

J. P. Fan ◽

C. Y. Tang ◽

C. L. Chow

Keyword(s):

Damage Model ◽

Tensile Loading ◽

Volume Element ◽

Damage Analysis ◽

Two Dimensional ◽

Element Computation ◽

Isotropic Damage ◽

Multi Level ◽

Abaqus Code ◽

Finite Element Computation

A multi-level superelement technique is applied to model the effects of circular voids on the effective elastic properties of a material. A two-dimensional representative volume element with a circular void in its center is initially modeled by a superelement. Using this superelement, a thin planar material with circular voids is constructed. The finite element computation is then conducted to estimate the effective Young’s modulus, Poisson’s ratio and the shear modulus of the material using the ABAQUS code for different void sizes. The values of the isotropic damage variables, DE and DG, under various degree of damage are hence determined. These values are compared with those calculated by using a conventional micromechanics damage model. A new isotropic damage model is proposed based on the results of this analysis. To demonstrate the applicability of this damage model, an example case of a notched cylindrical bar under tensile loading is investigated.

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