A Simple Method to Estimate the Vibration Characteristics of a PWR Fuel Assembly

2011 ◽  
Author(s):  
Hyeong Koo Kim ◽  
Kyou Seok Lee ◽  
Jeong Ha Kim ◽  
Sang Youn Jeon ◽  
Sun Tack Hwang
Keyword(s):  
Fuel Assembly ◽  
Vibration Characteristics ◽  
Mode Shapes ◽  
Test Results ◽  
Simple Method ◽  
Nuclear Fuel Assembly ◽  
Prototype Test ◽  
End Conditions ◽  
General Frequency ◽  
Supporting Condition

The main objective of this study is to establish a simple method making it possible to analyze the dynamic characteristics of the nuclear fuel assembly considering the geometrical configuration and the supporting condition of reactor internals etc. without any prototype test or FE models. In this study, a general frequency expression has been suggested for Bernoulli-Euler beams with generally restrained boundary conditions using Fourier series as a mode function. And using the frequency expression, the natural frequencies and mode shapes of a conventional fuel assembly for OPR1000 plants with reactor end conditions are calculated and compared with the test results in order to figure out its applicability to estimation on vibration characteristics of the fuel assembly. As a result, since the method suggested in present study gives quite a similar one with test result, present method will be useful to perform design evaluation preliminarily on the vibration characteristic of developing new fuel assembly.

Development of a Simplified PWR Fuel Assembly Nonlinear Model

2022 ◽  
Author(s):  
Namgyu Park ◽  
Youngik Yoo ◽  
Taesoon Kim ◽  
Sangyoun Jeon
Keyword(s):  
Fuel Assembly ◽  
Nonlinear Model ◽  
Element Model ◽  
Test Results ◽  
Unknown Parameters ◽  
Spacer Grids ◽  
Nuclear Fuel Assembly ◽  
Commercial Code ◽  
Nonlinear Finite Element Model ◽  
Skeleton Structure

Abstract This paper proposes a computation technique to develop a simplified nonlinear model for a typical nuclear fuel assembly. Because more than a hundred fuel assemblies are packed in the reactor, simplistic model generation is critical to evaluate the motion during an anticipated event such as earthquake. Two straight beams are introduced to simplify the fuel assembly, and the beam properties are moderately defined to represent the skeleton structure and a bundle of slender fuel rods. Because nonlinearity is caused by the interaction between the rods and the spacer grids in the skeleton structure, the two beams are connected with multilinear joints that characterize the mechanical interaction between them. An equation of motion for the model is provided, and the degree of the freedom of the model can be reduced by using a few major modes of the beams. Significant mechanical parameters must be defined reasonably, so a method is proposed to identify unknown parameters through a deterministic calculation and an optimization process. All the information, including the identified parameters, are utilized to develop a nonlinear finite element model with a commercial code. The performance of the model is compared with the test results.

IMPACT ANALYSIS AND TEST FOR THE SPACER GRID ASSEMBLY OF A NUCLEAR FUEL ASSEMBLY

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1228-1234 ◽  
Author(s):  
KEE-NAM SONG ◽  
SANG-HOON LEE ◽  
SOO-BUM LEE
Keyword(s):  
Fuel Assembly ◽  
Nuclear Fuel ◽  
Impact Analysis ◽  
Test Results ◽  
Lateral Loads ◽  
Spacer Grid ◽  
Element Analysis ◽  
Nuclear Fuel Assembly ◽  
Crush Strength ◽  
Good Agreement

A spacer grid assembly is one of the main structural components of the nuclear fuel assembly for a Pressurized light Water Reactor (PWR). The spacer grid assembly supports and aligns the fuel rods, guides the fuel assemblies past each other during a handling and, if needed, sustains lateral seismic loads. The ability of a spacer grid assembly to resist these lateral loads is usually characterized in terms of its dynamic and static crush strengths, which are acquired from tests. In this study, a finite element analysis on the dynamic crush strength of spacer grid assembly specimens is carried out. Comparisons show that the analysis results are in good agreement with the test results to within about a 30 % difference range. Therefore, we could predict the crush strength of a spacer grid assembly in advance, before performing a dynamic crush test. And also a parametric study on the crush strength of a spacer grid assembly is carried out by adjusting the weld penetration depth for a sub-sized spacer grid, which also shows a good agreement between the test and analysis results.

Vibration Characteristics of Three Representative Hydrofoil Configurations

1965 ◽  
Vol 9 (01) ◽  
pp. 23-38
Author(s):  
Guido E. Ransleben ◽  
Kishor D. Doshi ◽  
Jack T. Irick
Keyword(s):  
Theoretical Calculations ◽  
Mass Effect ◽  
Vibration Characteristics ◽  
Mode Shapes ◽  
Apparent Mass ◽  
Resonant Frequencies ◽  
Percent Agreement ◽  
Influence Coefficients ◽  
End Conditions ◽  
Modes Of Vibration

Comparisons are made between theoretical and measured resonant frequencies for three representative hydrofoil configurations (inverted pi, vee and inverted tee), with variable end conditions and depth of submergence in water. Theoretical calculations were based on influence coefficients, accounting for the "apparent mass" effect of the water. Agreement on frequencies through the first six to eight modes of vibration for all configurations is generally excellent, being well within 10 percent in most instances and in no case greater than 1 8.1 percent. Agreement on mode shapes is also generally good.

Vibration-based delamination evaluation in GFRP composite beams using ANN

2021 ◽  
pp. 096739112110033
Author(s):  
TG Sreekanth ◽  
M Senthilkumar ◽  
S Manikanta Reddy
Keyword(s):  
Finite Element ◽  
Natural Frequency ◽  
Composite Structures ◽  
Composite Beams ◽  
Vibration Characteristics ◽  
Mode Shapes ◽  
Aviation Industry ◽  
Frequency Data ◽  
Fiber Reinforced ◽  
Back Propagation Algorithm

Delamination is definitely an important topic in the area of composite structures as it progressively worsens the mechanical performance of fiber-reinforced polymer composite structures in its service period. The detection and severity analysis of delaminations in engineering areas like the aviation industry is vital for safety and economic considerations. The existence of delaminations varies the vibration characteristics such as natural frequencies, mode shapes, etc. of composites and hence this indication can be effectively used for locating and quantifying the delaminations. The changes in vibration characteristics are considered as inputs for the inverse problem to determine the location and size of delaminations. In this paper Artificial Neural Network (ANN) is used for delamination evaluationof glass fiber-reinforced composite beams using natural frequency as typical vibration parameter. The Finite Element Analysis is used for generating the required dataset for ANN. The frequency-based delamination prediction technique is validated by finite element models and experimental modal analysis. The results indicate that the ANN-based back propagation algorithm can predict the location and size of delaminations in composites with good accuracy for numerical natural frequency data but the accuracy is comparitivelyless for experimental natural frequency data.

Investigating the vibrational behaviour of a rotating two-blade propeller by using a self-tracking method

2018 ◽  
Vol 233 (3) ◽  
pp. 835-847 ◽  
Author(s):  
Mohammad-Reza Ashory ◽  
Farhad Talebi ◽  
Heydar R Ghadikolaei ◽  
Morad Karimpour
Keyword(s):  
Natural Frequency ◽  
Measurement Errors ◽  
Mode Shapes ◽  
Model Parameters ◽  
Test Results ◽  
Modal Assurance Criterion ◽  
Tracking Method ◽  
Strong Resemblance ◽  
Test Scenarios ◽  
Good Agreement

This study investigated the vibrational behaviour of a rotating two-blade propeller at different rotational speeds by using self-tracking laser Doppler vibrometry. Given that a self-tracking method necessitates the accurate adjustment of test setups to reduce measurement errors, a test table with sufficient rigidity was designed and built to enable the adjustment and repair of test components. The results of the self-tracking test on the rotating propeller indicated an increase in natural frequency and a decrease in the amplitude of normalized mode shapes as rotational speed increases. To assess the test results, a numerical model created in ABAQUS was used. The model parameters were tuned in such a way that the natural frequency and associated mode shapes were in good agreement with those derived using a hammer test on a stationary propeller. The mode shapes obtained from the hammer test and the numerical (ABAQUS) modelling were compared using the modal assurance criterion. The examination indicated a strong resemblance between the hammer test results and the numerical findings. Hence, the model can be employed to determine the other mechanical properties of two-blade propellers in test scenarios.

scholarly journals MS7001F Prototype Test Results

1989 ◽  
Author(s):  
D. E. Brandt
Keyword(s):  
Gas Turbine ◽  
Pressure Ratio ◽  
Load Test ◽  
Test Results ◽  
Critical Temperatures ◽  
Prototype Test ◽  
Surge Margin ◽  
Pertinent Data ◽  
Post Test ◽  
Heavy Duty Gas Turbine

The MS7001F heavy–duty gas turbine has been designed utilizing advanced analytical methods and a substantial array of component tests. The integrity of the system required that the prototype unit, with its accessories, be rigorously tested under load. The factory load test was completed on May 18, 1988 after 387 hours and 134 start/stop cycles. The MS7001F prototype gas turbine was instrumented with more than 3000 pieces of instrumentation in order to record all critical temperatures, pressures, flows, strains, displacements, and other pertinent data. The load device was a modified MS7001E compressor, which also supplied the means by which the MS7001F prototype compressor’s pressure ratio was increased to provide for surge margin determination. Inlet throttling of the MS7001F compressor allowed for full firing temperature operation, at reduced load. The results of this factory prototype load test are reported in the paper as are observations made during post test teardown.

scholarly journals Vibrational Analysis on Hemp and Okra Fibres Mixed Glass Fiber Polyester Composite

2021 ◽  
Vol 8 (11) ◽  
pp. 55-62
Author(s):  
Putti Venkata Siva Teja ◽  
Badatala Ooha ◽  
Kondeti Sravanth
Keyword(s):  
Glass Fiber ◽  
Natural Frequency ◽  
Natural Frequencies ◽  
Fiber Composite ◽  
Fem Analysis ◽  
Vibration Characteristics ◽  
Mode Shapes ◽  
Machine Component ◽  
Free System ◽  
Glass Fiber Composite

In transverse vibrations the element moves to and fro in a direction perpendicular to the direction of the advance of the wave. To determine the vibration characteristics i.e., natural frequencies and mode shapes, modal analysis is a process for a structure or a machine component while is being designed. In real life, aero planes, missiles, rockets, space vehicles, satellites, sub marines etc are modeled as free-free mechanical systems. In this paper an attempt was made to compare natural frequency for two composite materials- ladies finger with Glass fiber composite and Hemp with Glass fiber composite by taking as cantilever beams. The cantilever beam which is fixed at one end is vibrated to obtain the natural frequency, mode shapes at four different modes. A simple low cost demonstration experiment is performed in this paper by using common apparatus in order to compare theoretical, numerical (FEM analysis) profiles of two free-free thin two rectangular composite beams of dimensions 305*49.5* 7 in mm. Keywords: Natural frequencies, Mode shapes, Vibration characteristics, Ladies finger fiber, Hemp fiber, Glass fiber, FEM analysis, Free-Free system.

scholarly journals A Review on the Performance and Comfort of Stab Protection Armor

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Dereje Berihun Sitotaw ◽  
Dustin Ahrendt ◽  
Yordan Kyosev ◽  
Abera Kechi Kabish
Keyword(s):  
Protective Clothing ◽  
State Of The Art ◽  
Upper Body ◽  
Test Results ◽  
Safety Equipment ◽  
Freedom Of Movement ◽  
Prototype Test ◽  
Wear Comfort ◽  
Correction Officers ◽  
Security Control

Abstract Stab-protective clothing is the most important component of safety equipment and it helps to save the lives of its wearers; therefore, it is designed to resist knife, nail, or needle attacks, especially to the upper body. In this paper, the essential requirements for stab-resistant armor are investigated based on an in-depth review of previous research and prototype test results. The combination of protection and comfort in armor vests is a particularly challenging task. Review of the state of the art technology responsible for the manufacture of stab-resistant clothes has revealed that their design and development should encompass the elements of comfort, freedom of movement, permeability, absorption, evaporation, and weight reductions to ensure excellent ergonomics and high wear comfort. The design as well as the production, weight, thickness, material types and properties, and the arrangement of scales determine the level of protection and comfort offered by stab-resistant vests. Currently, the production of stab-proof gear-based 3D printing technology is evaluated, using lightweight materials (aramid) in the form of segmented scales inspired by nature. As the protection performance and wear comfort of stab-proof gear is enhanced, the willingness of security, control, transport, custom, and correction officers to wear them can be significantly increased in an endeavor to ensure that fatal injuries will decrease significantly.

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