Three-Dimensional Finite Element Analysis of Elastic-Plastic Crack Problems

1981 ◽  
Vol 103 (3) ◽  
pp. 214-218 ◽  
Author(s):  
B. V. Kiefer ◽  
P. D. Hilton
Keyword(s):  
Finite Element ◽  
Normal Stress ◽  
Crack Front ◽  
Stress Component ◽  
Three Dimensional ◽  
Specimen Thickness ◽  
Element Analysis ◽  
Finite Element Program ◽  
Elastic Plastic ◽  
Crack Problems

A three-dimensional, elastic-plastic finite element program is developed and applied to analyze the stress field in a plate containing a through crack. The center cracked plate is subjected to uniform tensile loading which results in mode I opening of the crack surfaces. Transverse variations of the opening tensile stress component and of the effective stress (von Mises) in the vicinity of the crack front are presented. They clearly demonstrate the three-dimensional nature of this problem with distributions that depend on specimen thickness. For thinner plates, the plastic deformation concentrates near the plate surfaces while the normal stress is largest in the plate interior. In thicker plates the deformation and normal stress fields are more uniform in the plate interior near the crack front, but they develop a rapid boundary layer-type variation in the vicinity of the plate surfaces.

Three-Dimensional Elastic-Plastic Finite-Element Analysis of the Flattening of Wire Between Plain Rolls*

2000 ◽  
Vol 123 (3) ◽  
pp. 397-404 ◽  
Author(s):  
H. Utsunomiya ◽  
P. Hartley ◽  
I. Pillinger
Keyword(s):  
Finite Element ◽  
Elastic Recovery ◽  
Three Dimensional ◽  
Lateral Spread ◽  
Radius Of Curvature ◽  
Forming Process ◽  
Empirical Formulas ◽  
Element Analysis ◽  
Finite Element Program ◽  
Elastic Plastic

It is normal industrial practice to roll round edged flat wires from round circular wires using plain rolls. Although this is not a complex type of metal forming process, the internal deformation is highly three-dimensional. It is important to be able to determine the lateral spread, elongation and final profile precisely. In this paper, this process has been analyzed using an elastic-plastic finite element program. Firstly, algorithms for integrating the constitutive equations, i.e., return mapping algorithms, are evaluated to determine the most accurate technique. Then, the influences of friction and reduction in thickness on the deformation characteristics are investigated. The lateral spread and the radius of curvature of the free surface are quantitatively in reasonable agreement with those obtained from empirical formulas. The lateral spread increases with friction and with reduction. The variation of elongation in the roll bite is investigated in detail. It is found that the elongation is not uniformly distributed across the cross section. After passing the roll gap, the distribution is compensated by the elastic recovery of wire, otherwise it may cause edge waves.

The Enriched Element for Finite Element Analysis of Three-Dimensional Elastic Crack Problems

1980 ◽  
Vol 102 (4) ◽  
pp. 347-352 ◽  
Author(s):  
P. D. Hilton ◽  
B. V. Kiefer
Keyword(s):  
Finite Element ◽  
Free Surface ◽  
Stress Intensity ◽  
Crack Front ◽  
Three Dimensional ◽  
Crack Edge ◽  
Element Analysis ◽  
Front Solution ◽  
Penny Shaped Crack ◽  
Crack Problems

An improved procedure for enriching three-dimensional isoparametric elements with the asymptotic crack front solution is described. Results from finite element calculations, involving these enriched elements, for the three-dimensional problems of a straight crack in plane strain and an axisymmetric penny-shaped crack which demonstrate the high degree of accuracy attainable are presented. Some finite-element solutions for through-crack and surface flaw problems are then reported showing the influence of a free surface on the variation of the stress intensity along the crack edge. Special treatments of the crack front-free surface stress intensity are implemented and the results discussed.

Effect of Adhesive Behavior on Normal Stress Distributions in the Single-Lap Adhesive Joints

2015 ◽  
Vol 1088 ◽  
pp. 769-773
Author(s):  
Xiao Cong He
Keyword(s):  
Finite Element ◽  
Normal Stress ◽  
Three Dimensional ◽  
Adhesive Layer ◽  
Elastic Stiffness ◽  
Adhesive Joints ◽  
Stress Distributions ◽  
Element Analysis ◽  
Element Technique ◽  
Three Dimensional Finite Element

The effect of adhesives behavior on the normal stress distributions of single-lap adhesive joints is investigated using the three-dimensional finite element technique. Numerical examples are provided to show the influence on the normal stresses of the joints using adhesives of different characteristics which encompass the entire spectrum of elastic stiffness behaviour. finite element analysis solutions of the normal stress distributions in the adhesive layer have been obtained for four typical characteristics of adhesives. The results indicate that Young’s modulus and Poisson’s ratios of adhesives strongly affect the normal stress distributions of the joints.

Incremental Variable Plastic Three-Dimensional Elastic-Plastic Finite Element Analysis in Soft Rock Tunnel Excavation

2014 ◽  
Vol 508 ◽  
pp. 243-248 ◽  
Author(s):  
Jun Peng Li ◽  
Xiao Li ◽  
Dong Qing Zhu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Soft Rock ◽  
Analysis Model ◽  
Element Analysis ◽  
Tunnel Excavation ◽  
Elastic Plastic ◽  
Stiffness Method ◽  
Rock Tunnel

The plane finite element analysis is mostly adopted in soft rock tunnel excavation instead of three-dimensional nonlinear finite element analysis at present, but almost every underground engineering is a spatial nonlinear problem which, in many cases, cannot be simplified into a plane problem. This paper presents a three-dimensional elastic-plastic finite element analysis of incremental variable plastic in soft rock tunnel excavation, through analyzing the tunnel excavation and support, and combining the incremental variable plastic stiffness method into three-dimensional elastic-plastic model in light of the advantage of increment variable stiffness method and the incremental additional load method. Simulation results show that, the three-dimensional elastic-plastic finite element analysis model presented in this paper changes little final deformation under different load release coefficients, together with small support stress.

Plastic Deformation Theory Application in Finite Element Analysis

2012 ◽  
Vol 594-597 ◽  
pp. 2723-2726
Author(s):  
Wen Shan Lin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Deformation Theory ◽  
Three Dimensional ◽  
Constitutive Laws ◽  
Constitutive Law ◽  
Element Analysis ◽  
Finite Element Program ◽  
Theory Of Plasticity ◽  
Element Program

In the present study, the constitutive law of the deformation theory of plasticity has been derived. And that develop the two-dimensional and three-dimensional finite element program. The results of finite element and analytic of plasticity are compared to verify the derived the constitutive law of the deformation theory and the FEM program. At plastic stage, the constitutive laws of the deformation theory can be expressed as the linear elastic constitutive laws. But, it must be modified by iteration of the secant modulus and the effective Poisson’s ratio. Make it easier to develop finite element program. Finite element solution and analytic solution of plasticity theory comparison show the answers are the same. It shows the derivation of the constitutive law of the deformation theory of plasticity and finite element analysis program is the accuracy.

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