Three-Dimensional Finite Element Simulations of Elastic and Elastic-Plastic Crack Growth Using Automated Re-Meshing Techniques

2014 ◽  
Author(s):  
Tyler London ◽  
Simon D. Smith ◽  
Şefika Elvin Eren
Keyword(s):  
Finite Element ◽  
Crack Growth ◽  
Three Dimensional ◽  
Offshore Structures ◽  
Element Analysis ◽  
Elastic Plastic ◽  
Dimensional Finite Element ◽  
Elastic Crack ◽  
Stability And Accuracy ◽  
Three Dimensional Finite Element

This paper concerns the numerical simulation of elastic and elastic-plastic crack growth in welded components. Three-dimensional, spline-based, automatic crack re-meshing algorithms have been developed at TWI to simulate crack propagation using the commercial finite element analysis software ABAQUS. These methods allow for fatigue crack growth simulations employing the Paris law, mean stress effects and more advanced elastic crack growth laws, and incorporate nodal release techniques or iterative stationary crack methods coupled with experimentally measured tearing resistance curves for elastic-plastic crack growth. The flexibility, stability and accuracy of these numerical methods are demonstrated through several examples. The application of the crack growth simulations to full-life engineering critical assessments (ECA) of offshore structures is also described and demonstrated.

Verification of Alternative Criteria for Shakedown Evaluation Using 2-Dimensional and 3-Dimensional Nozzle Models

2002 ◽  
Author(s):  
Seiji Asada ◽  
Asao Okamoto ◽  
Isoharu Nishiguchi
Keyword(s):  
Finite Element ◽  
3D Model ◽  
Three Dimensional ◽  
Evaluation Criteria ◽  
Symmetric Model ◽  
Element Analysis ◽  
Stress Evaluation ◽  
Elastic Plastic ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Alternative stress evaluation criteria suitable for Finite Element Analysis (FEA) proposed by Okamoto et al. [1] have been studied by the Committee on Three Dimensional Finite Element Stress Evaluation (C-TDF) in Japan. Thermal stress ratchet criteria in plastic FEA are now under consideration. Two criteria are proposed: evaluating variations in plastic strain increments and evaluating variations in the elastic core region. To verify the validity of these criteria, calculations were performed for several typical models in C-TDF [2]. This paper shows calculations and evaluation results of 2-dimensional and 3-dimentinal nozzles for shakedown and Ke-factors, as defined by equation 2. Two models are used. One is a 2-dimensional (2D) axi-symmetric model of a typical nozzle. The other is a 3-dimantional (3D) model of the nozzle of which shell radius is half of 2-dimensional model. The primary and secondary stress, shakedown analyses using elastic-plastic FEA and Ke-factors which are directly calculated from elastic-plastic FE analyses are surveyed. The results show that the alternative criteria are applicable for those models. The analysis results of the 2D model show good relation to those of the 3D model.

scholarly journals Probabilistic fatigue damage prognosis using surrogate models trained via three-dimensional finite element analysis

2016 ◽  
Vol 16 (3) ◽  
pp. 291-308 ◽  
Author(s):  
Patrick E Leser ◽  
Jacob D Hochhalter ◽  
James E Warner ◽  
John A Newman ◽  
William P Leser ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Crack ◽  
Crack Growth ◽  
Three Dimensional ◽  
High Fidelity ◽  
Probabilistic Prediction ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Utilizing inverse uncertainty quantification techniques, structural health monitoring (SHM) can be integrated with damage progression models to form a probabilistic prediction of a structure’s remaining useful life (RUL). However, damage evolution in realistic structures is physically complex. Accurately representing this behavior requires high-fidelity models which are typically computationally prohibitive. In this paper, high-fidelity fatigue crack growth simulation times are reduced by three orders of magnitude using a model based on a set of surrogate models trained via three-dimensional finite element analysis. The developed crack growth modeling approach is experimentally validated using SHM-based damage diagnosis data. A probabilistic prediction of RUL is formed for a metallic, single-edge notch tension specimen with a fatigue crack growing under mixed-mode conditions.

Finite Element Analysis of Nonuniformity of Tires with Imperfections5

2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Radial Force ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Force Variation ◽  
Three Dimensional Finite Element

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.

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