• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.6
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• pp.267-275
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• 1998

In this study, the instantaneous heat flux measurement probe and the linkage system for the measurement of the instantaneous temperature and heat flux of the DI mono cylinder diesel engine were developed, and these were proved to have a good reliability and sensibility. A 3-D FEM model which consist of full piston to accommodate the eccentric bowl in the piston head, was applied for the analysis of the thermal stress and the temperature distribution. The mean heat flux on the piston head was used as boundary condition for the analysis of piston. The analysis showed that thermal stress concentrate on the bowl and inner surface of pin hall.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.431-438
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• 2005

In this paper, the characteristics of excessive horizontal stress components in Korea were studied using the in-situ hydraulic fracturing stress measurement data over five hundred in 110 individual test boreholes. Based on the in-situ testing data, the magnitude and orientation of the horizontal stress component and variation of stress ratio (K) with depth were investigated. And also horizontal stress magnitude versus depth relationships and distribution limits of stress ratio components were suggested. For the subsurface space above 310 m depth in the entire territory, the stress ratio has a tendency to diminish and be stabilized with depth, but for some areas, it was revealed that the excessive horizontal stress fields with stress ratio close to 3.0 below 200 m in depth have formed. The result of investigation for excessive horizontal stress regions indicates that there exist several regions above 300 m in depth where localized excessive horizontal stresses enough to induce potentially brittle failure around future openings have formed.

• Journal of the Korean Society for Nondestructive Testing
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• v.10 no.1
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• pp.91-95
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• 1990

Welding residual stress was measured by Barkhausen noise method. The calibration experiment was done for the quantitative analysis. The specimen for the calibration experiment must has the same thermo-mechanical history as the actual material to be tested. The Barkhausen noise were analysed by the pulse-height distribution. The results show that the distribution and magnitude of welding residual stress from Barkhausen noise method are in good agreement with those from blind hole method.

• Transactions of Materials Processing
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• v.17 no.2
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• pp.107-112
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• 2008

In order to investigate the residual stress evolution during the leveling process of hot rolled high strength coils for cold forming, the in-plane residual stress of plate sampled at SPM, rough leveler and finish leveler were measured by cutting method. Residual stress was localized near the edge of plate. As the thickness of plate was increased, the size of residual stress region was expanded. The gradient of residual stress within the plate was reduced during the leveling process. But the residual stress itself was not removed completely within the ranges of tested conditions. The exact camber of cut plate was able to be predicted by the measurement of residual stress distribution after leveling of the plate.

• Journal of Korean Society of Steel Construction
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• v.9 no.4 s.33
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• pp.535-541
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• 1997

It is proper that the load distribution and the actual stress of members is analyzed by field measurement in estimating to the behavior of truss railway bridges, but those procedures are very difficult. So, the studies for the deduction of the stress, using the indirect data which are able to get from the research and investigation without field measurement, are needed. In this study, to investigate quantitically the variation of the stress of members, the stresses are obtained from the simulation which is considered the the reduction of the section area and the stiffness due to the corrosion and the degree of the stress ratio and the distribution is calculated. As the results, the stress of truss members is almost lineary increased to the decreasing of the area and the lower chord is greatly affected. And the increasing of the stress is predicted by the superposition to the results of the amount of that in each members.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.4
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• pp.401-408
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• 2009

This study is performed to check the three dimensional characteristics of residual stress in the dissimilar metal weld. Although two dimensional analysis has been widely used for the assessment of weld residual stress, it has limitations to understand the stress distribution of the third direction. 3-D analysis was done to understand residual stress distribution of the welded plate. A simple butt-welded plate was considered to show the stress variation on all direction. A mock-up plate weldment was fabricated with SA-508 and F316L, which are widely used in nuclear power plants. The analysis results were validated with the measured values in the mock-up.

• Journal of Korean Association for Spatial Structures
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• v.8 no.2
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• pp.63-72
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• 2008

One of the most important matters in keeping membrane structures in healthy condition is to maintain the proper tension distribution over the membrane. However, it is not easy to know the real stress level in the membrane quantitatively after completion of the structures. Authors suggested measurement method that can measure membrane stress using sound wave, and have been holding experimental tests of membrane stress measurement that used the sound external excitation with sine wave and white noise. The concept of the method is the fact that measurement of resonance frequency by vibrating membrane having rectangular boundary by audible frequency can measure membrane stress indirectly. In this paper, through the experimental tests it is proved that the equipment can be used for not only the membrane material of type A but also for types B and C. In addition, it is proved that the developed measurement equipment is available to stably measure the membrane stress which exists in the membrane material of the actual membrane structures.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.31 no.4
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• pp.41-48
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• 2008

The purpose of this study was to investigate the job stress factors that were related to the general characteristics, work characteristics, and health characteristics of the workers at distribution industry. The survey of job stress measurement scale for Korean employee which was developed by KOSHA and OSHRI in 2003 was used for this study. Three hundred and fifty workers at distribution industry participated in this study, and among them 326 responses were analyzed for this study due to the unreliability and insincerity of responses. Eight job stress factors like physical environment, self-control for the job, job unsecure, organization system, workplace culture, compensation for the job, relationship to the superior, and job requirement were analyzed. The results showed that the stress because of self control for the job was relatively higher than that of other industry workers. However, the stress because of physical environment, job requirement, job unsecure, organization system and compensation for the job was relatively lower than that of other industry workers. The female workers felt more stress than male workers in compensation for the job and workplace culture factors at distribution industry. The delivery and carrying job workers were more stressful than those of other jobs at distribution industry because of physical environments and self-control for the job. The non-regular job workers were more stressful than regular job workers in many stress factors like self-control for the job, job unsecure, organization system and compensation for the job.

• Nuclear Engineering and Technology
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• v.56 no.8
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• pp.3180-3187
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• 2024

Rupture disk corrosion test (RDCT) method has been recently developed for real-time measurement of initiation of stress corrosion cracking (SCC) in a high-temperature water. This work presents a parametric study on the stress distribution of a thin disk specimen of RDCT to consider the fixture shape and friction using finite element analysis (FEA). The FEA results showed a dome-shaped deformation of the specimen. From the stress analysis as a function of friction coefficient, it was suggested that the maximum stress was applied around the dome-edge, which was invariant with change to the friction coefficient. This indicates that friction between the fixture and the specimen has little effect on stress distribution. On the other hand, the stress analysis as a function of a rounded-corner radius (Rc) revealed the location at which the maximum stress was applied shifted from the dome edge to the dome center as Rc increased. From SCC initiation tests using the RDCT apparatus in a primary water environment, it was found that SCC initiates at the dome edge when Rc is 0.5 mm, while SCC initiates near the disk center when Rc is 2.0 mm. This experimental result is in good agreement with the results of FEA.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.510-516
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• 2005

This research aims to verify the stress distribution in soil according to the composition of the soil layer in case of surface loading. For this purpose, loading tests with measurement of stresses in the soil on four kinds of layered model ground in laboratory were performed. Those are (1)homogeneous sand, (2)gravel underlain by sand, (3)sand underlain by clay and (4)gravel underlain by clay. Test results are compared and analysed for the compositions of the soil layers. based on the results obtained, it is found that the larger the difference of the strengths of upper and lower layer is, the smaller the stress in the soil in case of surface loading is.