Development and Finite Element Implementation of Stress-Dependent Elastoviscoplastic Constitutive Model with Damage for Asphalt

2003 ◽  
Vol 1832 (1) ◽  
pp. 96-104 ◽  
Author(s):  
Andrew C. Collop ◽  
A. (Tom) Scarpas ◽  
Cor Kasbergen ◽  
Arian de Bondt
Keyword(s):  
Finite Element ◽  
Constitutive Model ◽  
Damage Mechanics ◽  
Compressive Strain ◽  
Local Strain ◽  
Continuum Damage Mechanics ◽  
Dependent Case ◽  
Strain Compatibility ◽  
Incremental Formulation ◽  
Stress Dependent

The development and finite element (FE) implementation of a stress-dependent elastoviscoplastic constitutive model with damage for asphalt is described. The model includes elastic, delayed elastic, and viscoplastic components. The strains (and strain rates) for each component are additive, whereas they share the same stress (i.e., a series model). This formulation was used so that a stress-based nonlinearity and sensitivity to confinement could be introduced into the viscoplastic component without affecting the behavior of the elastic and delayed elastic components. A simple continuum damage mechanics formulation is introduced into the viscoplastic component to account for the effects of cumulative damage on the viscoplastic response of the material. The model is implemented in an incremental formulation into the CAPA-3D FE program developed at Delft University of Technology in the Netherlands. A local strain compatibility condition is utilized such that the incremental stresses are determined explicitly from the incremental strains at each integration point. The model is demonstrated by investigating the response of a semirigid industrial pavement structure subjected to container loading. Results show that the permanent vertical strains in the non-stress-dependent case are significantly lower than the permanent vertical strains in the stress-dependent case. Results also show that in the stress-dependent case, there is a more localized area of high permanent vertical compressive strain directly under the load at approximately halfdepth in the asphalt compared with the non-stress-dependent case, in which the distribution is more even.

Progressive failure analysis of scarf-repaired composite laminate based on damage constitutive model

2016 ◽  
Vol 233 (2) ◽  
pp. 180-188 ◽  
Author(s):  
Qiuyi Shen ◽  
Zhenghao Zhu ◽  
Yi Liu
Keyword(s):  
Finite Element ◽  
Constitutive Model ◽  
Composite Laminate ◽  
Damage Mechanics ◽  
Cohesive Zone Model ◽  
Load Capacity ◽  
Three Dimensional ◽  
Zone Model ◽  
State Variables ◽  
Element Analysis

A three-dimensional finite element model for scarf-repaired composite laminate was established on continuum damage model to predict the load capacity under tensile loading. The mixed-mode cohesive zone model was adopted to the debonding behavior analysis of adhesive. Damage condition and failure of laminates and adhesive were subsequently addressed. A three-dimensional bilinear constitutive model was developed for composite materials based on damage mechanics and applied to damage evolution and loading capacity analyses by quantifying damage level through damage state variables. The numerical analyses were implemented with ABAQUS finite element analysis by coding the constitutive model into material subroutine VUMAT. Good agreement between the numerical and experimental results shows the accuracy and adaptability of the model.

Finite Element Simulation of the Creep Behavior of 2.25Cr-1Mo-0.25V Steel Based on Continuum Damage Mechanics

2015 ◽  
Vol 750 ◽  
pp. 266-271 ◽  
Author(s):  
Yu Zhou ◽  
Xue Dong Chen ◽  
Zhi Chao Fan ◽  
Yi Chun Han
Keyword(s):  
Genetic Algorithm ◽  
Finite Element ◽  
Creep Behavior ◽  
Constitutive Equations ◽  
Damage Evolution ◽  
Damage Mechanics ◽  
Creep Damage ◽  
Continuum Damage Mechanics ◽  
Continuum Damage ◽  
Element Simulation

The creep behavior of 2.25Cr-1Mo-0.25V ferritic steel was investigated using a set of physically-based creep damage constitutive equations. The material constants were determined according to the creep experimental data, using an efficient genetic algorithm. The user-defined subroutine for creep damage evolution was developed based on the commercial finite element software ANSYS and its user programmable features (UPFs), and the numerical simulation of the stress distribution and the damage evolution of the semi V-type notched specimen during creep were studied. The results showed that the genetic algorithm is a very efficient optimization approach for the parameter identification of the creep damage constitutive equations, and finite element simulation based on continuum damage mechanics can be used to analyze and predict the creep damage evolution under multi-axial stress states.

scholarly journals Constitutive Model for Concrete: An Overview

2015 ◽  
Vol 10 (Special-Issue1) ◽  
pp. 782-788 ◽  
Author(s):  
Mehdi Shekarbeigi ◽  
Hasan Sharafi
Keyword(s):  
Constitutive Model ◽  
Damage Mechanics ◽  
Constitutive Models ◽  
Continuum Damage Mechanics ◽  
Constitutive Modelling ◽  
Continuum Damage ◽  
Endochronic Theory ◽  
Small Deformations

In the last three decades, the constitutive modelling of concrete evolved considerably. This paper describes various developments in this field based on different approaches such anelasticity, plasticity, continuum damage mechanics, plastic fracturing, endochronic theory, microplane models, etc. In this article the material is assumed to undergo small deformations. Only time independent constitutive models and the issues related to their implementation are discussed

scholarly journals Failure Analysis of Composite Pinned Joints Based on Continuum Damage Mechanics

2018 ◽  
Vol 36 (5) ◽  
pp. 848-855
Author(s):  
Hongliang Tuo ◽  
Xiaoping Ma ◽  
Zhixian Lu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Damage Mechanics ◽  
Continuum Damage Mechanics ◽  
Element Model ◽  
Fracture Plane ◽  
Continuum Damage ◽  
Bearing Strength ◽  
Matrix Damage ◽  
Pinned Joints

The paper conducted bearing tests on composite pinned joints with four different stacking sequences. The bearing strength and bearing chord stiffness were obtained. The influence of stacking sequences on failure modes, bearing strength and bearing chord stiffness was discussed. Based on continuum damage mechanics, a three-dimensional finite element model of composite pinned joint under bearing load was built, where the maximum strain criterion was employed for initiation and bi-liner damage constitutive relation for revolution of fiber damage, while the physical-based Puck criterion was used for matrix damage initiation, and matrix damage revolution depended on the effective strain on the fracture plane. The failure mode, bearing strength and bearing chord stiffness of composite pinned joint were discussed with this model under which the non-linear shear behavior and in-situ strength effects were considered. Good agreements between test results and numerical simulations validates the accuracy and applicability of the finite element model.

A review of continuum damage and plasticity in concrete: Part II – Numerical framework

2021 ◽  
pp. 105678952110632 ◽  
Author(s):  
George Z Voyiadjis ◽  
Bilal Ahmed ◽  
Taehyo Park
Keyword(s):  
Finite Element ◽  
Damage Mechanics ◽  
Numerical Algorithms ◽  
Continuum Damage Mechanics ◽  
Future Research ◽  
Continuum Damage ◽  
Iterative Schemes ◽  
Rate Dependent ◽  
Concrete Damage ◽  
Open Issues

In this part II, companion article, we present the numerical review of continuum damage mechanics and plasticity in the context of finite element. The numerical advancements in local, nonlocal, and rate-dependent models are presented. The numerical algorithms, type of elements utilized in numerical analysis, the commercial software’s or in-house codes used for the analysis, iterative schemes, explicit or implicit approaches to solving finite element equations, and degree of continuity of element are discussed in this part. Lastly, some open issues in concrete damage modeling and future research needed are also discussed.

Finite Element Simulation of Damage in Dynamically Loaded Weldments

2000 ◽  
Author(s):  
Ricardo Moraes ◽  
David Nicholson
Keyword(s):  
Finite Element ◽  
Damage Mechanics ◽  
Continuum Damage Mechanics ◽  
Thermal Softening ◽  
Impulsive Loading ◽  
Published Data ◽  
Continuum Damage ◽  
Explicit Finite Element ◽  
Projectile Impact ◽  
Welded Structure

Abstract The main goal of the current investigation is to accommodate combined damage softening and thermal softening in structures that experience ductile fracture [1] due to an impulsive loading. A constitutive model first introduced by Johnson-Cook [2], which is sensitive to strain rate effects and temperature softening, is extended to explain the proposed idea. Equations are derived through continuum mechanics theory. Continuum Damage Mechanics (CDM) was first introduced by Kachanov [3] during the fifties. Since then, the topic has been under development by many authors. Numerical simulations are performed in the explicit finite element impact code LS-DYNA [4]. Constitutive equations for a viscoplastic model with damage and thermal softening are implemented in the code using a User Defined Subroutine UMAT. The Continuum Damage Mechanics (CDM) model is based on the Bonora formulation [5]. The combined material model, named UMAT 41, is added to the program static library using Digital Visual Fortran (FORTRAN 90). Using the User Defined Material, the solution of an explosive charge and of projectile impact applied to a ring-stiffened welded structure is analyzed to predict fracture. Ring-stiffened structures are widely used in ships, submarines and aircraft, which are subject to explosive or projectile attack. Results obtained using models with and without damage softening agree very well with previously published data with respect to crack paths. However, the time histories and thresholds are sensitive to the model used [6]. Projectile impact is also presented in this work.

Behavior of Lead-Free Solder Under Thermomechanical Loading

2004 ◽  
Vol 126 (3) ◽  
pp. 367-373 ◽  
Author(s):  
Y. Wei ◽  
C. L. Chow ◽  
K. J. Lau ◽  
P. Vianco ◽  
H. E. Fang
Keyword(s):  
Finite Element ◽  
Constitutive Model ◽  
Damage Mechanics ◽  
Base Alloy ◽  
Back Stress ◽  
General Purpose ◽  
Lead Free ◽  
Element Analysis ◽  
Different Temperatures ◽  
Free Solder

This paper presents an investigation of lead-free Sn-Ag base alloy, 95.5Sn-3.9Ag-0.6Cu, both experimentally and analytically. Experimentally, the deformation behavior of the material was measured for different temperatures (25°C and 1000°C) over a range of strain rates (10−5 to 10−3/s) under isothermal and thermomechanical conditions. Development of a unified viscoplastic constitutive model followed, taking into account the effects of the measured strain rate and temperature changes. The temperature rate effects are considered in the evolution equation of back stress. In order to include material degradation in the solder, the theory of damage mechanics is applied by introducing two damage variables in the viscoplastic constitutive model. Finally, the constitutive model is coded into a general-purpose finite element computer program (ABAQUS) through its user-defined material subroutine (UMAT). The damage-coupled finite element analysis (FEA) is then employed to monitor the condition of failure of a notched component. The predicted and measured maximum loads have been compared and found to be satisfactory. In addition, the calculated damage distribution contours enable the identification of potential failure site for failure analysis.

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