Automated Fracture Mechanics and Fatigue Analyses Based on Three-Dimensional Finite Elements

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Hitoshi Nakamura ◽  
Wenwei Gu ◽  
Seiichi Tajima ◽  
Osamu Hazama
Keyword(s):  
Finite Element ◽  
Crack Propagation ◽  
Three Dimensional ◽  
3D Fem ◽  
Element Mesh ◽  
Fem Model ◽  
Steel Pipes ◽  
Fatigue Initiation ◽  
Propagation Analysis ◽  
History Of

This paper describes the structure and application of a software system that automates the fatigue initiation and crack propagation analysis based on finite element method (FEM). The system automatically performs necessary procedures to track propagation history of cracks: insertion of a crack and updating of three-dimensional (3D) finite element mesh in accordance with the crack propagation. The system is equipped with a function to automatically perform fatigue analyses using the stress–strain histories at nodes of a 3D FEM model. Some analyses for several examples were carried out for validation. The important example is the surface crack propagation in steel pipes with residual stress.

Automated Fracture Mechanics and Fatigue Analyses Based on Three-Dimensional Finite Element for Welding Components

2014 ◽  
Author(s):  
Hitoshi Nakamura ◽  
Seiichi Tajima ◽  
Osamu Hazama ◽  
Wenwei Gu
Keyword(s):  
Finite Element ◽  
Fracture Mechanics ◽  
Crack Propagation ◽  
Low Cycle Fatigue ◽  
Three Dimensional ◽  
Hexahedral Mesh ◽  
Element Mesh ◽  
Fem Model ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

This paper describes the structure and application of a software system that automates the fatigue initiation and crack propagation analysis based on FEM. The system automatically performs necessary procedures to track propagation history of cracks: insertion of a crack and updating of three-dimensional finite element mesh in accordance with the crack propagation. Most of the meshing is carried out by a Delaunay tessellation method. A tubular hexahedral mesh is generated at the crack front and the fracture mechanics parameters are computed using commercial codes to ensure accuracy. The generation of this tubular hexahedral mesh is fully automatic as well. The system is equipped with a function to automatically perform fatigue analyses using the stress-strain histories at nodes of a three-dimensional FEM model. The standard low cycle fatigue analysis approach is adopted. Using the function, cumulative fatigue for a given FEM model is provided. Some analyses for several examples were carried out for validation. The important example is the surface crack propagation in steel pipes with residual stress.

On Mixed Mode Crack Propagation Analysis Based on VCCM (Virtual Crack Closure-Integral Method) for Tetrahedral Finite Element

2010 ◽  
Author(s):  
Hiroshi Okada ◽  
Hiroshi Kawai ◽  
Takashi Tokuda ◽  
Yasuyoshi Fukui
Keyword(s):  
Finite Element ◽  
Crack Propagation ◽  
Crack Closure ◽  
Integral Method ◽  
Three Dimensional ◽  
Finite Element Program ◽  
Propagation Analysis ◽  
Element Program ◽  
Analysis System ◽  
Automatic Mesh

The authors have been developing a crack propagation analysis system that can model arbitrary shaped cracks in three-dimensional solids. In the system, automatic mesh generation program, parallel/large finite element program (ADVENTURE_Solid) and virtual crack closure-integral method (VCCM) for the quadratic tetrahedral finite element are used as its key-components. In this paper, the components in the crack propagation system are briefly described and some demonstration problems are presented for an illustrative purposes.

scholarly journals Crack propagation analysis in selected railway bogie components

2020 ◽  
pp. 1-10
Author(s):  
Adam Mysłek
Keyword(s):  
Finite Element ◽  
Crack Propagation ◽  
Extended Finite Element Method ◽  
Practical Application ◽  
Extended Finite Element ◽  
Element Mesh ◽  
Damage Initiation ◽  
Propagation Analysis ◽  
Location Change ◽  
Brake Calliper

This paper presents the practical application of fracture mechanics in investigating the possibility of crack propagation in a brake calliper bracket mounted in a vehicle bogie. The extended finite element method available in the Abaqus software was used. This method allows the modelling of material damage and its propagation independently of the finite element mesh. Damage can arise in any area of finite elements without changing the mesh. Numerical simulation of crack propagation was performed in order to analyse how crack changes as a result of the location change of damage initiation.

ADDITIONAL PROPERTIES OF THE NODE-BASED SMOOTHED FINITE ELEMENT METHOD (NS-FEM) FOR SOLID MECHANICS PROBLEMS

2009 ◽  
Vol 06 (04) ◽  
pp. 633-666 ◽  
Author(s):  
T. NGUYEN-THOI ◽  
G. R. LIU ◽  
H. NGUYEN-XUAN
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Upper Bound ◽  
Solid Mechanics ◽  
Three Dimensional ◽  
Element Mesh ◽  
Fem Model ◽  
Volumetric Locking ◽  
Smoothed Finite Element Method ◽  
Element Method

A node-based smoothed finite element method (NS-FEM) for solving solid mechanics problems using a mesh of general polygonal elements was recently proposed. In the NS-FEM, the system stiffness matrix is computed using the smoothed strains over the smoothing domains associated with nodes of element mesh, and a number of important properties have been found, such as the upper bound property and free from the volumetric locking. The examination was performed only for two-dimensional (2D) problems. In this paper, we (1) extend the NS-FEM to three-dimensional (3D) problems using tetrahedral elements (NS-FEM-T4), (2) reconfirm the upper bound and free from the volumetric locking properties for 3D problems, and (3) explore further other properties of NS-FEM for both 2D and 3D problems. In addition, our examinations will be thorough and performed fully using the error norms in both energy and displacement. The results in this work revealed that NS-FEM possesses two additional interesting properties that quite similar to the equilibrium FEM model such as: (1) super accuracy and super-convergence of stress solutions; (2) similar accuracy of displacement solutions compared to the standard FEM model.

Optimization of the Wrist Pin End of an Automobile Engine Connecting Rod With an Interference Fit

1990 ◽  
Vol 112 (3) ◽  
pp. 406-412 ◽  
Author(s):  
Vijay Sarihan ◽  
Ji Oh Song
Keyword(s):  
Finite Element ◽  
Optimum Design ◽  
Three Dimensional ◽  
Stress Singularity ◽  
Design Strategy ◽  
Structural Components ◽  
Connecting Rod ◽  
Fem Model ◽  
Automobile Engine ◽  
Interference Fit

Current design procedures for complicated three-dimensional structural components with component interactions may not necessarily result in optimum designs. The wrist pin end design of the connecting rod with an interference fit is governed by the stress singularity in the region where the wrist pin breaks contact with the connecting rod. Similar problems occur in a wide variety of structural components which involve interference fits. For a better understanding of the problems associated with obtaining optimum designs for this important class of structural interaction only the design problems associated with the wrist pin end of the rod are addressed in this study. This paper demonstrates a procedure for designing a functional and minimum weight wrist pin end of an automobile engine connecting rod with an interference fit wrist pin. Current procedures for Finite Element Method (FEM) model generation in complicated three-dimensional components are very time consuming especially in the presence of stress singularities. Furthermore the iterative nature of the design process makes the process of developing an optimum design very expensive. This design procedure uses a generic modeler to generate the FEM model based on the values of the design variables. It uses the NASTRAN finite element program for structural analysis. A stress concentration factor approach is used to obtain realistic stresses in the region of the stress singularity. For optimization, the approximate optimization strategy in the COPES/CONMIN program is used to generate an approximate design surface, determine the design sensitivities for constrained function minimization and obtain the optimum design. This proposed design strategy is fully automated and requires only an initial design to generate the optimum design. It does not require analysis code modifications to compute the design sensitivities and requires very few costly NASTRAN analyses. The connecting rod design problem was solved as an eight design variable problem with five constraints. A weight reduction of nearly 27 percent was achieved over an existing design and required only thirteen NASTRAN analyses. It is felt that this design strategy can be effectively used in an engineering environment to generate optimum designs of complicated three-dimensional components.

Combining Serial Sectioning, EBSD Analysis, and Image-Based Finite Element Modeling

MRS Bulletin ◽  
2008 ◽  
Vol 33 (6) ◽  
pp. 597-602 ◽  
Author(s):  
G. Spanos ◽  
D.J. Rowenhorst ◽  
A.C. Lewis ◽  
A.B. Geltmacher
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Electron Backscatter Diffraction ◽  
Three Dimensional ◽  
Research Area ◽  
Polycrystalline Materials ◽  
Serial Sectioning ◽  
3D Fem ◽  
Element Modeling ◽  
The Status

AbstractThis article first provides a brief review of the status of the subfield of three-dimensional (3D) materials analyses that combine serial sectioning, electron backscatter diffraction (EBSD), and finite element modeling (FEM) of materials microstructures, with emphasis on initial investigations and how they led to the current state of this research area. The discussions focus on studies of the mechanical properties of polycrystalline materials where 3D reconstructions of the microstructure—including crystallographic orientation information—are used as input into image-based 3D FEM simulations. The authors' recent work on a β-stabilized Ti alloy is utilized for specific examples to illustrate the capabilities of these experimental and modeling techniques, the challenges and the solutions associated with these methods, and the types of results and analyses that can be obtained by the close integration of experiments and simulations.

Dynamic crack propagation analysis based on the s-version of the finite element method

2020 ◽  
Vol 366 ◽  
pp. 113091
Author(s):  
Kota Kishi ◽  
Yuuki Takeoka ◽  
Tsutomu Fukui ◽  
Toshiyuki Matsumoto ◽  
Katsuyuki Suzuki ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Crack Propagation ◽  
Dynamic Crack Propagation ◽  
Dynamic Crack ◽  
The Finite Element Method ◽  
Propagation Analysis ◽  
Element Method
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