scholarly journals XFEM Simulation of Tensile and Fracture Behavior of Ultrafine-Grained Al 6061 Alloy

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1761
Author(s):  
Saurabh Gairola ◽  
Rengaswamy Jayaganthan
Keyword(s):  
Stress Intensity Factor ◽  
Finite Element ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Fracture Behavior ◽  
Al Alloys ◽  
J Integral ◽  
Extended Finite Element ◽  
Al 6061 ◽  
Number Of Cycles

In the present work, the tensile and fracture behavior of ultra-fine grained (UFG) Al 6061 alloy was simulated using extended finite element method (XFEM). UFG Al 6061 alloy processed by cryorolling (CR) and accumulative roll bonding (ARB) was investigated in this work. Numerical simulations of two-dimensional and three-dimensional models were performed in “Abaqus 6.14” software using an elastic-plastic approach, and the results obtained were validated with the experimental results. The specimens corresponding to the three-point bend test, compact tension test with center crack, and double edge cracks were analyzed using XFEM (eXtended Finite Element Method) approach. In XFEM, the partition of unity (PU) was used to model a crack in the standard finite element mesh. The tensile and fracture properties obtained from the simulation were in tandem with the experimental data. UFG Al alloy showed higher tensile strength and fracture toughness compared to their bulk solution treated counterparts. Fracture toughness was measured in terms of stress intensity factor and J integral. In CR Al alloys, with increasing thickness reduction, an increase in stress intensity factor and a decrease in the J integral was observed. This behavior is attributed to the increase in strength and decrease in ductility of CR samples with increasing thickness reduction. In ARB Al alloys, the strength and ductility have increased with an increase in number of cycles. It also revealed an increase in both the stress intensity factor and J integral in ARB processed Al alloys with increase in number of cycles, as evident from XFEM simulation results.

Finite Element Fracture Mechanics Study of Pre-Northridge Connections

2006 ◽  
Vol 324-325 ◽  
pp. 1007-1010 ◽  
Author(s):  
Hong Bo Liu ◽  
Chang Hai Zhai ◽  
Yong Song Shao ◽  
Li Li Xie
Keyword(s):  
Stress Intensity Factor ◽  
Finite Element ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Fracture Behavior ◽  
Integral Approach ◽  
J Integral ◽  
Finite Element Analyses ◽  
Element Analysis ◽  
Weld Root

The objective was to quantify the variation of stress intensity factor to weld root flaw sizes in steel frame connections. Finite-element analyses were used to study fracture toughness in welded beam-column connections. Investigations of fracture behavior mainly focused on the standard pre-Northridge connection geometry. Finite element analysis was performed using the ANSYS computer program. Stress intensity factor was calculated through a J-integral approach. Results show that stress intensity factor is not uniform and is largest in the middle of beam flange. Stress intensity factor increases nearly linear with the increase of flaw size. Backing bars have little effect on weld fractures.

Application of Extended Finite Element Method (XFEM) to Stress Intensity Factor Calculations

2015 ◽  
Author(s):  
Do-Jun Shim ◽  
Mohammed Uddin ◽  
Sureshkumar Kalyanam ◽  
Frederick Brust ◽  
Bruce Young
Keyword(s):  
Finite Element Method ◽  
Stress Intensity Factor ◽  
Finite Element ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Degrees Of Freedom ◽  
Extended Finite Element Method ◽  
Partition Of Unity ◽  
Extended Finite Element ◽  
Element Method

The extended finite element method (XFEM) is an extension of the conventional finite element method based on the concept of partition of unity. In this method, the presence of a crack is ensured by the special enriched functions in conjunction with additional degrees of freedom. This approach also removes the requirement for explicitly defining the crack front or specifying the virtual crack extension direction when evaluating the contour integral. In this paper, stress intensity factors (SIF) for various crack types in plates and pipes were calculated using the XFEM embedded in ABAQUS. These results were compared against handbook solutions, results from conventional finite element method, and results obtained from finite element alternating method (FEAM). Based on these results, applicability of the ABAQUS XFEM to stress intensity factor calculations was investigated. Discussions are provided on the advantages and limitations of the XFEM.

J-Integral Evaluation for Calculating Structural Intensity and Stress Intensity Factor Using Commercial Finite Element (FE) Solutions

2013 ◽  
Vol 650 ◽  
pp. 379-384 ◽  
Author(s):  
Jong Wan Hu
Keyword(s):  
Stress Intensity Factor ◽  
Finite Element ◽  
Stress Intensity ◽  
Fracture Mechanics ◽  
Intensity Factor ◽  
Integral Approach ◽  
J Integral ◽  
Fe Modeling ◽  
Linear Elastic ◽  
Structural Intensity

This report is mainly performed to investigate finite element (FE) modeling and post-processing capacities for fracture mechanics analyses characterized by the stress intensity factor (SIF) at successively stationary crack tip positions. As part of a linear elastic fracture mechanics (LEFM) analysis, the determination of stress intensity factor distribution can also be adopted by J-integral approach. The aim of this report is to review three papers related to estimate J-integrals through FE study and represent the theoretical backgrounds. Furthermore, the technical details for both FE modeling and SIF evaluation will be described in this report based on complete understanding of three reference papers. These numerical approaches to deal with SIF evaluation of general cracks can be applied in 2D and 3D FE models.

Top Beam Flange Fracture Behavior in Steel Frame Connections under Gravity Loads

2007 ◽  
Vol 348-349 ◽  
pp. 381-384
Author(s):  
Hong Bo Liu ◽  
Chang Hai Zhai ◽  
Yong Song Shao ◽  
Li Li Xie
Keyword(s):  
Stress Intensity Factor ◽  
Finite Element ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Fracture Behavior ◽  
Steel Frame ◽  
Integral Approach ◽  
Element Analysis ◽  
Frame Building ◽  
Weld Root

Top beam flange fractures were observed in the post-earthquake steel frame building inspections. Both seismic loads and gravity loads have effect on top beam flange fractures. The objective was to quantify the variation of stress intensity factor to weld root flaw sizes on top of the beam flange at column face in steel frame connections under gravity loads. Finite-element analyses were used to study fracture toughness in welded beam-column connections. Investigations of fracture behavior mainly focused on the standard pre-Northridge connection geometry. Finite element analysis was performed using the ANSYS computer program. Stress intensity factor was calculated through a J-integral approach. The parametric study was conducted to quantify elastic fracture demands as a function of beam geometries. Results show that the distributions of stress intensity factor tend to be even across the flange width under gravity loads. The thickness of beam web has little effect on stress intensity factors. Stress intensity factor increases nearly linear with the increase of flaw size, and it increases with the increase of depth of beam and width of beam. Stress intensity factor reduces with the increase of thickness of beam flange.

Numerical Study of Stress Intensity Factor in Notched Specimens Using Extended Finite Element Method

2012 ◽  
Vol 166-169 ◽  
pp. 2995-2998
Author(s):  
Geng Chen ◽  
Tao Xu ◽  
Qiang Xu ◽  
Lin Bu
Keyword(s):  
Finite Element Method ◽  
Stress Intensity Factor ◽  
Finite Element ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Numerical Simulations ◽  
Extended Finite Element Method ◽  
Extended Finite Element ◽  
Notched Specimens ◽  
Element Method

The principle of the structure of displacement function, the establishment of governing equations, level set method were briefly outlined in this paper. Numerical simulations on three dimensional single edge notched specimens with different crack length in tension were performed using Abaqus software based on extended finite element method (XFEM), the stress intensity factor at static crack front was analyzed and the simulated results were in good agreement with analytical solutions. Numerical simulations in the present paper indicated that the extended finite element method is very suitable to deal with nonlinear fracture problems.

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