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.

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 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.

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.

Grinding Damage Prediction for Ceramics via CDM Model

1999 ◽  
Vol 122 (1) ◽  
pp. 51-58 ◽  
Author(s):  
Bi Zhang ◽  
Xianghe Peng
Keyword(s):  
Damage Mechanics ◽  
Coupling Effect ◽  
Three Dimensional ◽  
Continuum Damage Mechanics ◽  
Inelastic Behavior ◽  
Finite Element Program ◽  
Damage Prediction ◽  
Grinding Conditions ◽  
Element Program ◽  
Three Dimensional Finite Element

A continuum damage mechanics (CDM) model is proposed to predict grinding damage of ceramics. The model takes into account the inelastic behavior of ceramics, the effect of grinding induced hydrostatic pressure and the coupling effect between volumetric and deviatoric deformations on damage. A numerical algorithm is proposed and a three-dimensional finite element program is developed for the model. Damage is analyzed for silicon nitride ceramics subjected to single grit grinding conditions. The damage predicted by the model shows good agreement to the measurement results obtained by experiments. The model can also be used to predict grinding damage for other types of materials. [S1087-1357(00)70301-7]

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.

Friction Force and Stresses Analysis for Contact of Assembled Details

2006 ◽  
Vol 113 ◽  
pp. 334-338
Author(s):  
Z. Dreija ◽  
O. Liniņš ◽  
Fr. Sudnieks ◽  
N. Mozga
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Plastic Deformation ◽  
Friction Force ◽  
Sliding Friction ◽  
Friction Model ◽  
Contact Interface ◽  
Finite Element Program ◽  
Elastic Plastic ◽  
Element Program

The present work deals with the computation of surface stresses and deformation in the presence of friction. The evaluation of the elastic-plastic contact is analyzed revealing three distinct stages that range from fully elastic through elastic-plastic to fully plastic contact interface. Several factors of sliding friction model are discussed: surface roughness, mechanical properties and contact load and areas that have strong effect on the friction force. The critical interference that marks the transition from elastic to elastic- plastic and plastic deformation is found out and its connection with plasticity index. A finite element program for determination contact analysis of the assembled details and due to details of deformation that arose a normal and tangencial stress is used.

Mechanical Property Analysis and Numerical Simulation of Honeycomb Sandwich Structure’s Core

2013 ◽  
Vol 631-632 ◽  
pp. 518-523 ◽  
Author(s):  
Xiang Li ◽  
Min You
Keyword(s):  
Numerical Simulation ◽  
Elastic Constants ◽  
Sandwich Structure ◽  
Optimization Design ◽  
Simulation Analysis ◽  
Finite Element Program ◽  
Honeycomb Sandwich ◽  
Calculation Results ◽  
Element Program ◽  
Typical Satellite

Owing to the lack of a good theory method to obtain the accurate equivalent elastic constants of hexagon honeycomb sandwich structure’s core, the paper analyzed mechanics performance of honeycomb sandwich structure’s core and deduced equivalent elastic constants of hexagon honeycomb sandwich structure’s core considering the wall plate expansion deformation’s effect of hexagonal cell. And also a typical satellite sandwich structure was chose as an application to analyze. The commercial finite element program ANSYS was employed to evaluate the mechanics property of hexagon honeycomb core. Numerical simulation analysis and theoretical calculation results show the formulas of equivalent elastic constants is correct and also research results of the paper provide theory basis for satellite cellular sandwich structure optimization design.

Finite Element Analysis on the Deformation of Energy-Saving Wire-Mesh Frame Wallboard

2014 ◽  
Vol 501-504 ◽  
pp. 731-735
Author(s):  
Li Zhang ◽  
Kang Li
Keyword(s):  
Finite Element ◽  
Energy Saving ◽  
Theoretical Basis ◽  
Steel Wire ◽  
Wire Mesh ◽  
Design Parameters ◽  
Element Analysis ◽  
Finite Element Program ◽  
Element Program ◽  
Influence Degree

This paper analyzes the influence degree of related design parameters of wire-mesh frame wallboard on deformation through finite element program, providing theoretical basis for the design and test of steel wire rack energy-saving wallboard.

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