• Journal of the Korean Society of Mechanical Technology
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• v.13 no.1
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• pp.11-16
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• 2011

When the trains are passed the station, a serious force is applied to ground and the caused vibration is propagated to the area of the station by the ground and rocks. The caused vibration brings about the operation interruption of the equipment which is sensitive to the vibration, or will bring about the structural damage of the station. In this study, to investigate the vibrational evaluation of railway station by the train service, the vibration simulation was performed and analyzed the effect of the vibration isolating countermeasure. From the vibration measurement, all trains that passed through the station exceeded the vibration criteria. Therefore, the vibration isolating countermeasure was established and the vibration simulation was performed.

• Structural Engineering and Mechanics
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• v.19 no.3
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• pp.237-260
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• 2005

This paper presents an experimental as well as a numerical analysis of the in-plane shear behaviour of hollow, $870{\times}840{\times}100mm$ masonry walls, externally strengthened with FRP composites. The experimental approach is devoted to the evaluation of the effectiveness of different composite strengthening configurations and the methodology consists in the diagonal compression of masonry walls. The numerical study assesses the stress and strain state distribution in the unreinforced and strengthened panels using a commercial finite element code. The effect of FRP reinforcement on the masonry behaviour and the capability of modelling to forecast a representative failure mode of the unreinforced and reinforced masonry walls is investigated.

• Structural Engineering and Mechanics
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• v.17 no.6
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• pp.829-862
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• 2004

This paper presents a method for the nonlinear analysis of beam elements subjected to the cyclical combined actions of torsion, biaxial flexure and axial forces based on an extension of the disturbed compression field (DSFM). The theoretical model is based on a hybrid formulation between the full rotation of the cracks model and the fixed direction of the cracking model. The described formulation, which treats cracked concrete as an orthotropic material, includes a new approach for the evaluation of the re-orientation of both the compression field and the deformation field by removing the restriction of their coincidence. A new equation of congruence permits evaluating the deformation of the middle line. The problem consists in the solution of coupled nonlinear simultaneous equations expressing equilibrium, congruence and the constitutive laws. The proposed method makes it possible to determine the deformations of the beam element according to the external stresses applied.

• Earthquakes and Structures
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• v.1 no.2
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• pp.177-195
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• 2010

This paper presents an appraisal of four nonlinear static procedures (CSM, N2, MPA and ACSM) employed in seismic assessment of plan-irregular buildings. It uses a three storey reinforced concrete plan-irregular frame building exemplifying typical older constructions of the Mediterranean region in the early 1970s that was tested in full-scale under bi-directional pseudo-dynamic loading condition at JRC, Ispra. The adequacy and efficiency of the simplified analytical modelling assumptions adopted were verified. In addition, the appropriate variants of code-prescribed NSPs (CSM and N2) to be considered for subsequent evaluation were established. Subsequent parametric studies revealed that all such NSPs predicted reasonably well both global and local responses, having the benchmark values been determined through nonlinear dynamic analyses using a suit of seven ground motions applied with four different orientations. The ACSM, however, predicted responses that matched slightly better the median dynamic results.

• Earthquakes and Structures
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• v.10 no.3
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• pp.629-643
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• 2016

Among all the natural disasters, earthquakes are the most destructive calamities since they cause a plenty of injuries and economic losses leaving behind a series of signs of panic. The present study highlights the moment-curvature relationships for the structural elements such as beam and column elements and Non-Linear Static Pushover Analysis of RC frame structures since it is a very simplified procedure of non-linear static analysis. The highly popular model namely Mander's model and Kent and Park model are considered and then, seismic risk evaluation of RC building has been conducted using SAP 2000 version 17 treating uncertainty in strength as a parameter. From the obtained capacity and demand curves, the performance level of the structure has been defined. The seismic fragility curves were developed for the variations in the material strength and damage state threshold are calculated. Also the comparison of experimental and analytical results has been conducted.

• Smart Structures and Systems
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• v.10 no.1
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• pp.47-65
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• 2012

The presence of crack-like defects in mechanical and structural elements produces failures during their service life that in some cases can be catastrophic. So, the early detection of the fatigue cracks is particularly important because they grow rapidly, with a propagation velocity that increases exponentially, and may lead to long out-of-service periods, heavy damages of machines and severe economic consequences. In this work, a non-destructive method for the detection and identification of elliptical cracks in shafts based on stress wave propagation is proposed. The propagation of a stress wave in a cracked shaft has been numerically analyzed and numerical results have been used to detect and identify the crack through the genetic algorithm optimization method. The results obtained in this work allow the development of an on-line method for damage detection and identification for cracked shaft-like components using an easy and portable dynamic testing device.

• Wind and Structures
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• v.17 no.3
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• pp.345-359
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• 2013

Turkey has been hosted various civilizations throughout centuries and it has become one of the oldest settlements all over the world due to the geographical location. Therefore, it has accommodated innumerable historical structures remain from the past civilizations. Protection and conservation of these historical constructions should be the major points for continuity of history. Crooked minaret is one of between these historical invaluable structures. It is located at the city of Aksaray and it dates back approximately 800 years. The minaret has lost its vertical position in time and bends on the North-West direction. In this study, general information is given about minarets and some restoration recommendations are given for crooked minaret based on performed some finite element structural analyses. These analyses are considered into three cases; 1-Dead loading, 2-Wind loading, and 3-Earthquake loadings. Results from the analyses are discussed detailed and some useful recommendations are given in the end of the study.

• Proceedings of the Safety Management and Science Conference
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• 2008.11a
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• pp.145-152
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• 2008

Single PPM Quality Innovation Movement is originally developed quality program in Korea for supplier's quality level-up since 1995. The quality target is below the 10ppm(parts per million) in outgoing quality and delivered goods plus field claim. This Single PPM Quality Innovation Movement program was conducted to realize the anticipated results not only due to management result level's increasing, but also the company's confidence and competitiveness. This study attempted to find the mutual influences on the participation of the constituent members, satisfaction of the constituent members and results of the management from Single PPM Quality Innovation Movement. The reliance analysis for the measurement material on the questionnaire was verified by Cronbach's alpha coefficient. Participation of the constituent members, satisfaction of the constituent member and result of the management, the influences upon Single PPM improvement degree level were verified through the structural analysis by using SPSS statistic package. The influence evaluation among the groups was evaluated by the structure equation.

• Proceedings of the KSR Conference
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• 1999.11a
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• pp.181-188
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• 1999

For weight reduction of the gearbox of power bogie of high speed train, aluminum alloy is recommended for the material of the gerabox case. In this paper, three models(Steel G/B Case-Steel BRG. Case[model-S], Aluminum G/B Case-Aluminum BRG. Case[model-A], Aluminum G/B Case-Steel BRG. Case[model-AS]) were compared to each other in the view of thermal expansion. The evaluation of the internal load, thermal expansion deformation and lug analysis were executed. It results that the 'model-A' is excessively deformed and fail in the bolt hole of bearing case. Material change of the bearing case to steel(model-AS) is effective to restrain the deformation of the inner radios of the bearing case and to prevent the failure of that.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1501-1514
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• 2008

Recently, so as to solve the urban transportation problem the LRT(Light Rail Transit) system has been studied on the essential technology and the engineering know-how, which lead lower construction cost and higher reliability. The localization development of rubber tired AGT(Automatic Guided Trainsit) system has performed from 1999 to 2004, as a national project of the Minister of Land, Transport and Maritime Affairs. For the application of the rubber tired AGT system in Busan Subway 3-2 Line, this study is focused on the reliability of aluminium profiles vehicle carbody and the establishment of the test and evaluation technologies. In this paper, 3D modeling simulation was applied to the load test of aluminium vehicle carbody. The reliability of the vehicle carbody was estimated as the fatigue test of welded aluminium profiles. From the test and simulation results, it could be concluded that the developed rubber tired AGT shows a good structural reliability and integrity.