Prediction of Fracture and Fatigue Damage in Engineering Structures

2002 ◽  
Author(s):  
Y. Wei ◽  
C. L. Chow
Keyword(s):  
Fatigue Damage ◽  
Damage Mechanics ◽  
Evolution Equations ◽  
Material Degradation ◽  
Engineering Structures ◽  
Finite Element Program ◽  
Plastic Damage ◽  
Element Program ◽  
Theory Of Damage ◽  
Al 2024

This paper presents a method of failure analysis based on the theory of damage mechanics to predict fracture and fatigue failure in engineering structures. Two damage surfaces, the fatigue damage surface and the plastic damage surface, are firstly introduced to characterize material degradation. Then the damage evolution equations are provided. A failure criterion is proposed using the concept of damage accumulation. The model is incorporated into a commercial finite element program ABAQUS, which is used to conduct failure analyses in components made of AL 2024-T3 under both monotonic loading and cyclic loading.

scholarly journals Characteristics of Creep Damage for 60 Sn-40 Pb Solder Material

1999 ◽  
Vol 123 (3) ◽  
pp. 278-283 ◽  
Author(s):  
Y. Wei ◽  
C. L. Chow ◽  
H. E. Fang ◽  
M. K. Neilsen
Keyword(s):  
Damage Mechanics ◽  
Evolution Equations ◽  
Damage Model ◽  
Creep Damage ◽  
General Purpose ◽  
Tensile Creep ◽  
Finite Element Program ◽  
Solder Material ◽  
Phase Size ◽  
Element Program

This paper presents a viscoplasticity model taking into account the effects of change in grain or phase size and damage on the characterization of creep damage in 60 Sn-40 Pb solder. Based on the theory of damage mechanics, a two-scalar damage model is developed for isotropic materials by introducing the free energy equivalence principle. The damage evolution equations are derived in terms of the damage energy release rates. In addition, a failure criterion is developed based on the postulation that a material element is said to have ruptured when the equivalent damage accumulated in the element reaches a critical value. The damage coupled viscoplasticity model is discretized and coded in a general-purpose finite element program known as ABAQUS through its user-defined material subroutine UMAT. To illustrate the application of the model, several example cases are introduced to analyze, both numerically and experimentally, the tensile creep behaviors of the material at three stress levels. The model is then applied to predict the deformation of a notched specimen under monotonic tension at room temperature (22°C). The results demonstrate that the proposed model can successfully predict the viscoplastic behavior of the solder material.

scholarly journals The impact of drilling and slitting construction on damage field: evolution characteristics in low-permeability coal seam

2021 ◽  
Vol 37 ◽  
pp. 205-215
Author(s):  
Heng Chen ◽  
Hongmei Cheng ◽  
Aibin Xu ◽  
Yi Xue ◽  
Weihong Peng
Keyword(s):  
Finite Element ◽  
Rock Mass ◽  
Damage Mechanics ◽  
Effective Strain ◽  
Secondary Development ◽  
Distribution Area ◽  
Finite Element Program ◽  
Element Program ◽  
Mining Face ◽  
The Impact

ABSTRACT The fracture field of coal and rock mass is the main channel for gas migration and accumulation. Exploring the evolution law of fracture field of coal and rock mass under the condition of drilling and slitting construction has important theoretical significance for guiding efficient gas drainage. The generation and evolution process of coal and rock fissures is also the development and accumulation process of its damage. Therefore, based on damage mechanics and finite element theory, the mathematical model is established. The damage variable of coal mass is defined by effective strain, the elastoplastic damage constitutive equation is established and the secondary development of finite element program is completed by FORTRAN language. Using this program, the numerical simulation of drilling and slitting construction of the 15-14120 mining face of Pingdingshan No. 8 Mine is carried out, and the effects of different single borehole diameters, different kerf widths and different kerf heights on the distribution area of surrounding coal fracture field and the degree of damage are studied quantitatively. These provide a theoretical basis for the reasonable determination of the slitting and drilling arrangement parameters at the engineering site.

Damage Mechanism Research of Yushu Airport Road Landslide No.3 Base on Elastoplastic Damage Constitutive Model

2015 ◽  
Vol 744-746 ◽  
pp. 464-469
Author(s):  
Hong Gang Wu ◽  
Tao Yang ◽  
Xiao Yun Chen ◽  
Hui Min Ma ◽  
Hong Li Zhang ◽  
...  
Keyword(s):  
Constitutive Model ◽  
Damage Mechanism ◽  
Earthquake Triggering ◽  
Triggering Mechanism ◽  
Finite Element Program ◽  
Plastic Damage ◽  
Mechanism Research ◽  
Element Program ◽  
Damage Constitutive Model ◽  
Stability Of Slope

Due to the earthquake of Yushu in April 14, 2010, Airport Road landslide No.3 deformed cracking, resulting in lower stability of slope, triggering landslides and other diseases. Selecting the section 2-2 (mileage K823 + 809) of Airport Road landslide No.3 as the calculation section, we use the ABAQUS finite element program to establish landslide numerical mode. The slip mass of landslide was simulated by the elastic-plastic damage constitutive model, and the bedrock was analyzed as Mohr - Coulomb constitutive model. Landslide No3 is analyzed for example, and showed that earthquake triggering mechanism elastplastic damage constitutive model can describe the landslide very well.

A Simple Plastic-Damage Model for the Cement-Soil Admixture

2007 ◽  
Vol 353-358 ◽  
pp. 1145-1148 ◽  
Author(s):  
X.J. Yu ◽  
Zhen Fang ◽  
Shan Yong Wang ◽  
Yun Yan ◽  
Jian Hua Yin
Keyword(s):  
Damage Mechanics ◽  
Damage Model ◽  
Critical Index ◽  
Fortran Program ◽  
Compression Tests ◽  
Material Degradation ◽  
Softening Behaviour ◽  
Plastic Damage ◽  
Basic Equations ◽  
Cement Soil

An Elastic Plastic-Damage (EPD) model is developed to model the softening behaviour of the cement-soil admixture based on continuous damage mechanics. The softening behaviour is considered to be characteristic outcome of the material degradation due to damage in material. Material degradation is modelled by reducing progressively the stiffness and yield stress of the material when the damage variable has attained a critical index. The basic equations of the model are derived and presented. A Fortran program for this model has been developed and implemented into a finite element code ABAQUS. In order to evaluate the applicability of this model, several unconfined compression tests are simulated using ABAQUS with this model. The computed results are compared with measured data and good agreement is achieved.

Viscoplastic Constitutive Modeling of Anisotropic Damage Under Nonproportional Loading

2000 ◽  
Vol 123 (4) ◽  
pp. 403-408 ◽  
Author(s):  
C. L. Chow ◽  
X. J. Yang ◽  
Edmund Chu
Keyword(s):  
Constitutive Modeling ◽  
Damage Evolution ◽  
Damage Mechanics ◽  
Evolution Equations ◽  
Forming Limit ◽  
Anisotropic Damage ◽  
Limit Curve ◽  
Forming Limit Curve ◽  
Localized Necking ◽  
Theory Of Damage

Based on the theory of damage mechanics, a viscoplastic constitutive modeling of anisotropic damage for the prediction of forming limit curve (FLC) is developed. The model takes into account the effect of rotation of principal damage coordinates on the deformation and damage behaviors. With the aid of the damage viscoplastic potential, the damage evolution equations are established. Based on a proposed damage criterion for localized necking, the model is employed to predict the FLC of aluminum 6111-T4 sheet alloy. The predicted results agree well with those determined experimentally.

FE Modeling of FRP-Concrete Interface for very High Cycle Fatigue Behavior

2013 ◽  
Vol 577-578 ◽  
pp. 165-168 ◽  
Author(s):  
M. Mahal ◽  
T. Blanksvärd ◽  
B. Täljsten
Keyword(s):  
Fatigue Damage ◽  
High Cycle Fatigue ◽  
Fatigue Behavior ◽  
Three Dimensional ◽  
Fatigue Loading ◽  
Cycle Fatigue ◽  
Finite Element Program ◽  
Element Program ◽  
Three Dimensional Finite Element ◽  
Concrete Interface

The fatigue damage of FRP-concrete interface is a major problem in strengthened structures subjected to fatigue loading. The available FRP-concrete interface models published in the literature usually deal with fracture mechanism approach, which is unsuitable for high cycle fatigue damage. In this study, a constitutive micro model is developed for FRP-concrete interface for high cycle fatigue and incorporated into a three dimensional finite-element program. Numerical analysis of a double lap joint is carried out, and the results show that the proposed model is reasonably accurate.

A Material Model for Prediction of Fatigue Damage and Degradation of CFRP Materials

2017 ◽  
Vol 742 ◽  
pp. 740-744 ◽  
Author(s):  
Jörg Hohe ◽  
Monika Gall ◽  
Hannes Gauch ◽  
Sascha Fliegener ◽  
Zalkha Murni binti Abdul Hamid
Keyword(s):  
Fatigue Damage ◽  
Low Cycle Fatigue ◽  
Damage Model ◽  
Material Model ◽  
Finite Element Program ◽  
Damage Evolution Equation ◽  
Brittle Damage ◽  
Linear Elastic ◽  
Element Program ◽  
Definition Of

Objective of the present study is the definition of a material model accounting for fatigue damage and degradation. The model is formulated as a brittle damage model in the otherwise linear elastic framework. A stress driven damage evolution equation is derived from microplasticity considerations. The model is implemented as a user-defined material model into a commercial finite element program. In a comparison with experimental data in the low cycle fatigue regime, a good agreement with the numerical prediction is obtained.

A Study of Microdeformation and Creep-Fatigue Damage using Acoustic Emission Technique

1988 ◽  
Vol 142 ◽  
Author(s):  
Yunxu Liu ◽  
Xingren Li
Keyword(s):  
Plastic Deformation ◽  
Fatigue Damage ◽  
High Performance ◽  
Damage Mechanics ◽  
High Strength Steels ◽  
High Strength ◽  
Optical Microscope ◽  
Plastic Deformation Behavior ◽  
Creep Fatigue ◽  
Theory Of Damage

AbstractThis paper deals with the relationship between the plastic deformation damage and microstructure by means of Acoustic Emmission. The plastic deformation behavior of AISI 4340 steel of various microstructures was investigated in both the tensile and creep-fatigue testings with a view to providing new insights into properties of high performance steel. Based on Theory of Damage Mechanics, a creep-fatigue law was derived and formulated. The reason of early failure and the service life prophecy of high strength steels was studied.The damage micromechanism of four stages was studied by the optical microscope, scanning electron microscope, and microhardness tester. It seems that the nucleation and the growth of the voids at the martensiteferrite interface is the dominant mechanism of damage. The monitoring of Acoustic Emmission indicated that the plastic deformation did not appear in the circulating hardening stage. But in the circulating softening stage, the accumulation of the plastic deformation and the creep-fatigue damage become more and more severe. The total energy of Acoustic Emmission was successfully applied to measure the degree of the damage caused by the plastic deformation.

Research on Distribution and Evolution Law of the Damage-Fracture Field in Mining Process

2011 ◽  
Vol 243-249 ◽  
pp. 5964-5967 ◽  
Author(s):  
Ai Bin Xu ◽  
Feng Gao ◽  
Hong Mei Cheng ◽  
Xing Guang Liu
Keyword(s):  
Damage Mechanics ◽  
Volumetric Strain ◽  
Gas Extraction ◽  
Spatiotemporal Evolution ◽  
Finite Element Program ◽  
Evolution Law ◽  
Excavation Process ◽  
Element Program ◽  
Damage Field ◽  
Strain Stress

The distribution and spatiotemporal evolution law of the mining-induced fracture field was studied by means of damage mechanics. The damage variable correlated with the excavation process was introduced, which was used to describe the distribution characteristics of fractures in rock mass. In accordance with the damaged theory, the elastic finite element program was developed, by which the analysis of mining process of one coal seam was made of. The material damage accumulation taken into consideration, the distribution and evolution law of the volumetric strain, stress and damage field was obtained, which provided a theoretic reference for the design of gas drainage and improving the efficiency of gas extraction.

Damage Evolution of Laminated Composites Using Continuum Damage Mechanics Incorporate with Interface Element

2008 ◽  
Vol 385-387 ◽  
pp. 277-280 ◽  
Author(s):  
Bijan Mohammadi ◽  
Hossein Hosseini-Toudeshky ◽  
Mohammad Homayoun Sadr-Lahidjani
Keyword(s):  
Damage Mechanics ◽  
Axial Loading ◽  
Continuum Damage Mechanics ◽  
Matrix Cracking ◽  
Interface Element ◽  
Progressive Damage ◽  
Continuum Damage ◽  
Finite Element Program ◽  
Initiation And Propagation ◽  
Element Program

In this paper, 3D continuum damage mechanics (CDM) incorporated with layer-wise theory and interface element is employed to investigate the progressive damage inside and between the laminate's layers under quasi-static axial loading. For this purpose, a finite element program is developed. To simulate the delamination, a quadratic interface element is used which is compatible with the 8-node numerical layers of layer-wise theory. Matrix cracking and delamination initiation and propagation of [302/-302]s angle-ply laminate are investigated and the obtained results are compared with the available experimental evidence.

Sign in / Sign up

Export Citation Format

Share Document