An Approach for Assessing Fuel Assembly’s Structural Integrity Under In-Core Operating Conditions Using Finite Element Method

2009 ◽  
Author(s):  
Wei Zhao ◽  
Yuriy Aleshin
Keyword(s):  
Finite Element ◽  
Lateral Load ◽  
Operating Conditions ◽  
Growth Effect ◽  
Structural Behavior ◽  
Design Stage ◽  
Structural Components ◽  
Early Design ◽  
Early Design Stage ◽  
Spring Force

This paper describes the development and application of a single fuel assembly (FA) finite element analysis (FEA) model that can be used to assess and predict the structural behavior of FA during its entire life at early design stage. This model includes all structural components of a FA and has been validated under laboratory test conditions, including spacer grid test under axial load, skeleton test under axial and lateral load, FA test under axial and lateral load, as well as the fuel rod drag test. The model is then applied to an example FA design by predicting the FA’s in-core behavior, including its growth characteristics due to irradiation, and irradiation-induce creep and hydrogen absorption; effect of spring force relaxation of structural spacer grids; effect of holddown spring force increase with growth; effect of different amounts of initial FA bow and bowed shapes; FA distortion evolution vs. burnup history; and stress and deformation of various structural components. It demonstrates that this approach can be used to assess fuel assembly’s structural behavior under various operating conditions at early design stage.

Combined Approximation Reanalysis Coupled With Finite Element Stress Analysis for Multiple Geometric Changes in Early Design Stage

2005 ◽  
Author(s):  
Sachin S. Terdalkar ◽  
Joseph J. Rencis
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Design Stage ◽  
Finite Element Technique ◽  
Early Design ◽  
Early Design Stage ◽  
Machine Element ◽  
Element Technique ◽  
Geometric Changes

In this work a new graphically driven interactive stress reanalysis finite element technique has been developed so that an engineer can easily carry out manual geometric changes in a machine element during the early design stage. The interface allow an engineer to model a machine element in the commercial finite element code ANSYS® and then modify part geometry graphically to see instantaneous graphical changes in the stress and displacement contour plots. A reanalysis technique is used to enhance the computational performance for solving the modified problem; with the aim of obtaining results of acceptable accuracy in as short a period of time in order to emphasize the interactive nature of the design process. Two case studies are considered to demonstrate the effectiveness of the prototype graphically driven reanalysis finite element technique. The finite element type considered is a plane stress four-node quadrilateral based on a homogenous, isotropic, linear elastic material. Each case study considered multiple redesigns. A combined approximation reanalysis method is used to solve each redesigned problem. The first case study considers a plate with a hole with the goal to determine the hole shape that will minimize the stress concentration. The second case study considers a support bracket. The goal is to design the cantilever portion of the bracket to have uniform strength and to minimize the stress concentration at the fillet.

Identification of Human Errors During Early Design Stage Functional Failure Analysis

2018 ◽  
Author(s):  
Lukman Irshad ◽  
Salman Ahmed ◽  
Onan Demirel ◽  
Irem Y. Tumer
Keyword(s):  
Failure Analysis ◽  
Human Error ◽  
System Level ◽  
Design Stage ◽  
Human Factors Engineering ◽  
Human Errors ◽  
Functional Failure ◽  
Early Design ◽  
Early Design Stage ◽  
Early Design Stages

Detection of potential failures and human error and their propagation over time at an early design stage will help prevent system failures and adverse accidents. Hence, there is a need for a failure analysis technique that will assess potential functional/component failures, human errors, and how they propagate to affect the system overall. Prior work has introduced FFIP (Functional Failure Identification and Propagation), which considers both human error and mechanical failures and their propagation at a system level at early design stages. However, it fails to consider the specific human actions (expected or unexpected) that contributed towards the human error. In this paper, we propose a method to expand FFIP to include human action/error propagation during failure analysis so a designer can address the human errors using human factors engineering principals at early design stages. To explore the capabilities of the proposed method, it is applied to a hold-up tank example and the results are coupled with Digital Human Modeling to demonstrate how designers can use these tools to make better design decisions before any design commitments are made.

A Numerical Approach for the Prediction and Reduction of Structure-Borne Noise During the Design Stage of Ground Vehicles

1993 ◽  
Author(s):  
Nickolas Viahopoulos ◽  
Edward V. Shalis ◽  
Michael A. Latcha
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Numerical Approach ◽  
Design Stage ◽  
Structural Components ◽  
Ground Vehicles ◽  
Radiated Noise ◽  
Forcing Function ◽  
Military Applications ◽  
Commercial Applications

Abstract During the design stage of ground vehicles it is important to reduce the noise emitted from structural components. In commercial applications the reduction of the interior noise for passenger comfort is a concern with increased significance. In military applications noise radiated from the exterior of the vehicle is of primary importance for the survivability of the vehicle. Numerical acoustic prediction software can be used during the design stage to predict and reduce the radiated noise. Two formulations, the Rayleigh integral equation1 and the direct boundary element method2,3 were implemented into software for acoustic prediction. The developed code can accept information from a finite element model with a known input forcing function. Specifically, the predicted velocities on the structural surfaces can be used as input to the acoustic code for predicting the noise emitted from a vibrating structure. Computation of acoustic sensitivities4 was also implemented in the code. This information can identify the portions of the boundary that effect the radiated noise most, and it can be used in an optimization process to reduce the noise radiated from a vibrating structure.

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