• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.651-656
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• 2004

This paper presents the application of Differential Transformation to the bucking load and the vibration problem of the rectangular plate loaded by varying in-plane stress. Numerical calculations are carried out and compared with previously published results to validate the results of the resent method. The results obtained by this method agree well with those reported in the Devious works. The results obtained by the present method are presented for various non-uniform loads.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.3
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• pp.110-116
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• 2002

Here are shown on stress and vibration evaluations and application of piping system in petrochemical plant with and actual example. While stress evaluation by thermal growth has no argument on the calculated results, vibrational evaluations have some different results in accordance with the evaluation methods. In case of the static stress evaluation the ASME B3l.3 code defines 7000 cycles of fatigue lift: in operating the piping system with a design condition. However, the method of vibrational evaluation on piping systems in petrochemical plants has not been established clearly, yet. In this stuffy, it is purposed to present the requirement of a vibrational evaluation method for petrochemical plant piping system, with an actual application.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.612-617
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• 2014

It is generally known that the automotive road wheel involves the non-proportional multiaxial loading condition, therefore the measuring dynamic stress and strain in driving state is very important to predict an endurance characteristic of the automotive road wheel. In this study, the ultimate driving test using F1 circuit with respect to 2 kinds of velocity conditions have been carried out in order to measure dynamic stress, strain of the wheel and acceleration of a vehicle. Based on the measured results, the characteristics of dynamic stress generation have been analyzed, and factors which have effect on the dynamic stress generation have been studied.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1061-1064
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• 2006

Optimal design of functionally graded plates is investigated considering stress and critical temperature. Material properties are assumed to be temperature dependent and varied continuously in the thickness direction. The effective material properties are obtained by applying linear rule of mixtures. The 3-D finite element model is adopted using an 18-node solid element to analyze more accurately the variation of material properties and temperature field in the thickness direction. For stress analysis, the tensile stress ratio and compressive stress ratio of the structure under mechanical load are investigated. In the thermo-mechanical buckling analysis, temperature at each node is obtained by solving the steady-state heat transfer problem and Newton-Raphson method is used for material nonlinear analysis. Finally, the optimal design of FGM plates is studied for stress reduction and improving thermo-mechanical buckling behavior, simultaneously.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.888-892
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• 2003

This study was tested for the bending stress analysis of Experimental stress analysis on various ankle foot orthoses(AFOs) was fulfilled. Stress was measured by Strain gages which were attached on 8 region in AFOs Results revealed that the peak compressive/tensile stress in the orthoses occured in the lateral region of neck. The Stress Analysis system was made by the electronic oscilloscope, strain gage sensors, amplifier, A/D converter, PC with C program It will be able to using the important data in splint design. Selected AFOs were some different materials but all have same shape except one type(orthosis with joint). C program Is used for managing data. Thus lateral side of the neck region is failed easily.

• Steel and Composite Structures
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• v.51 no.2
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• pp.103-116
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• 2024

Based on the consistent couple stress theory (CCST), we develop a unified formulation for analyzing the static bending and free vibration behaviors of functionally graded (FG) microscale beams (MBs). The strong forms of the CCST-based Euler-Bernoulli, Timoshenko, and Reddy beam theories, as well as the CCST-based sinusoidal, exponential, and hyperbolic shear deformation beam theories, can be obtained by assigning some specific shape functions of the shear deformations varying through the thickness direction of the FGMBs in the unified formulation. The above theories are thus included as special cases of the unified CCST. A comparative study between the results obtained using a variety of CCST-based beam theories and those obtained using their modified couple stress theory-based counterparts is carried out. The impacts of some essential factors on the deformation, stress, and natural frequency parameters of the FGMBs are examined, including the material length-scale parameter, the aspect ratio, and the material-property gradient index.

• Journal of Environmental Science International
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• v.13 no.6
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• pp.581-589
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• 2004

This paper describes the amount of food consumption and the change of total weight of abalone under a vibration with noise that can be occurred due to piling work. This experiment was conducted in the aquarium in Yosu National University. In normal situation the juvenile stage shell's(total length is 1～1.5cm) amount of food consumption was 0.81g, the middle stage shell(total length is 3～3.5cm) was 13.61g, and the adult stage shell (Total length is 7～7.5cm) was 43.l9g per 5 organisms in 24 hours, while the experimental group was observed low numerical value compared normal groups. The abalones' food consumption and total weight in both groups, the intermittent and continuance impact with noise and vibration, was reduced during this experiment. The abalones' food consumption and total weight in the experimental groups without vibration were recorded slightly high numerical value than the experimental groups with noise and vibration. Based on this experimental data we could conjecture the noise and vibration are harmful factors to bring up a physiological stress to abalones. Especially, the vibration impact by piling works could produce a considerably unfavorable effect to the abalones than noise impact.

• Journal of Sensor Science and Technology
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• v.29 no.3
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• pp.205-210
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• 2020

The aim of this study is to develop a vertical vibration compensator that attenuates the vertical vibration of ships. The vibration compensator was designed according to the principle of generating vertical excitation forces by rotating two eccentric bodies of the same mass in opposite directions at the same rotational speed. In addition, the structural stability was analyzed using the finite element method. The maximum stress in the drive shaft was 95.6 MPa, which was approximately 35% of the allowable stress of the shaft material (SM45C, 270 MPa). The acceleration signals of the vibrator compensator body and the testbed were determined to evaluate the efficiency of the vibration compensator and the designed excitation forces. Subsequently, the excitation forces were estimated based on the relationship between force and acceleration. The estimated results were very close to the theoretical values with an error of less than 3%.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.253-253
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• 2008

The main purpose of this study is to identify the vibrational characteristics for the LP blades of Korean standard fossil power plants. Modal tests for the 6 stage blade with boundary condition in which the root of blades are constrained with the disk were conducted, and FE analysis was also did with the same boundary condition. The steady-stress and modal analyses for the coupled bladed-disk system of LP turbine stages were completed. The dynamic analysis and fatigue analysis were followed to diagnose the integrity of LP turbine blades.

• Journal of Korean Society of Steel Construction
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• v.10 no.4 s.37
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• pp.601-613
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• 1998

This paper reports the first-of-its-kind free vibration solutions for sectorial plates having re-entrant corners causing stress singularities when the circular edge is either clamped or simply supported. The Ritz method is employed with two sets of admissible functions assumed for the transverse vibratory displacements. Accurate frequencies and normalized contours of the transverse vibratory displacement are presented for the spectra of sector angles.