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.

THREE DIMENSIONAL FINITE ELEMENT SIMULATION OF THE FRETTING WEAR PROBLEMS

2006 ◽  
Vol 20 (25n27) ◽  
pp. 3890-3895 ◽  
Author(s):  
CHOON YEOL LEE ◽  
JOON WOO BAE ◽  
BYUNG SUN CHOI ◽  
YOUNG SUCK CHAI
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Fretting Wear ◽  
Symmetric Model ◽  
Two Dimensional ◽  
Element Analysis ◽  
Inconel 690 ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

The structural integrity of steam generators in nuclear power plants is very much dependent upon the fretting wear characteristics of Inconel 690 U-tubes. In this study, a finite element analysis was used to investigate fretting wear on the secondary side of the steam generator, which arises from flow-induced vibrations (FIV) between the U-tubes and supports or foreign objects. Two-dimensional and three-dimensional finite element analyses were adopted to investigate the fretting wear problems. The purpose of the two-dimensional analysis, which simulated the contact between a punch and a plate, was to demonstrate the validity of using finite element analysis to analyze fretting wear problems. This was achieved by controlling the value of the wear constant and the number of cycles. The two-dimensional solutions obtained from this study were in good agreement with previous results reported by Strömberg. In the three-dimensional finite element analysis, a quarterly symmetric model was used to simulate tubes contacting at right angles. The results of the analyses showed donut-shaped wear along the contacting boundary, which is a typical feature of fretting wear.

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.

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.

Sign in / Sign up

Export Citation Format

Share Document