• Journal of the Korean Society for Railway
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• v.7 no.2
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• pp.77-84
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• 2004

In order to determine the most suitable material system for achieving the lightweight design while fulfilling the design requirements of carbody structures of Korean Tilting Train eXpress(TTX), aluminum carbody. composite carbody, and hybrid carbody combined with aluminum and composite structures were considered in the present study. The finite-element analysis was used to verify the design requirements or the TTX carbody structures with the material system considered in the design stages. The stresses in the carbody structures and deflections of underframe against static load cases were used as design criteria. The results show that the hybrid carbody structures are beneficial with regard to weight savings and structural integrity in comparison to aluminum and composite carbody structures.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.462-467
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• 2004

In order to determine the most suitable material system which can achieve the lightweight design and fulfill the design requirements of carbody structures of Korean Tilting Train eXpress (TTX), aluminum carbody, composite carbody, and hybrid carbody combined with aluminum and composite structures were considered in present study. The finite-element analysis was used to verity the design requirements of the TTX carbody structures with the material system being considered in the design stages. The stresses in the carbody structures and deflections of underframe against static load cases were checked as design criteria. The results show that the hybrid carbody structures are beneficial with regard to weight savings and structural integrity when compared to aluminum and composite carbody structures.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.04a
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• pp.199-202
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• 2005

This study has performed the static loading tests for the composite train body of Korean tilting train. The structural tests based on the JIS E7105 standard were carried out in the test facility designed for the train carbody. The vertical, compressive and torsional loads were imposed on the underframe and the end structure of the carbody. the structural behavior of the carbody under the 3-point supporting and the natural frequency were evaluated as well. In addition, the test results were compared with the numerical one. From the tests. the structural strength of the hybrid composite carbody was assessed.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.98-102
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• 2003

The use of composite materials for the carbody structures of tilting train has many advantages because of manufacturing variety, specific high-strength & stiffness characteristics, and long-life durability, but the strongest advantage is the possibility of lightweight product. In the leading countries, the composite materials are used for the material for drivers' cabs, interior/exterior equipments for railway train, and it is now developing the composite materials applied for the train carbody structure. In this paper, we conducted the evaluation of structural stability for the all aluminum carbody, all composite carbody and hybrid carbody structures of the Korean Tilting Train eXpress(TTX) with the service speed of 180km/h.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2003.10a
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• pp.203-206
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• 2003

Using composite materials for the carbody of tilting train has many advantages such as manufacturing variety, specific high-strength ＆ stiffness characteristics, and long-life durability, but the strongest advantage could be the possibility of lightweight product. In the leading countries, the composite materials are used for the material fur drivers'cabs, interior/exterior equipments for railway train, and it is now developing the composite materials applied for the train carbody structure. In this paper, we conducted the evaluation of structural stability for the aluminum and composite carbody of the Korean Tilting Train express(TTX) with the service speed of 180km/h.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.4 s.247
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• pp.473-480
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• 2006

This paper explains analytical and experimental studies to evaluate the natural frequency of a composite carbody of Korean tilting train. The composite carbody with length of 23m was manufactured as a sandwich structure composed of 40mm-thick aluminium honeycomb core and 5mm-thick woven fabric carbon/epoxy face. From the finite element analysis, the 1st bending and 1st twisting natural frequency of the composite carbody were 11.67Hz and 14.4Hz, respectively. In order to verify the analytical results, the natural frequency measuring tests were performed. The measured 1st bending and twisting natural frequencies of the composite carbody were 10.25Hz and 11.0Hz, respectively. Both of these results satisfied the design requirement.

• Journal of the Korean Society for Railway
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• v.9 no.3 s.34
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• pp.251-256
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• 2006

This paper explains manufacturing process, analysis and experimental studies on a hybrid composite carbody of Korean tilting train. The composite carbody with length of 23m was manufactured as a sandwich structure composed of a aluminium honeycomb core and woven fabric carbon/epoxy faces. In order to evaluate deformational behavior of the composite carbody, the static load test under vertical load has been conducted. From the test, the vertical deflection an겨 cross sectional deformation of the carbody were analysed and measured. The maximum deflection along the side sill was 9.25mm in the experiment and 8.28mm in the analysis. The maximum cross sectional deformation was measured 5.42mm at carbody center in lateral direction and 4.06mm at roof center in vertical direction.

• Journal of the Korean Society for Railway
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• v.9 no.2 s.33
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• pp.145-150
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• 2006

In this study, overturning safety for a tilting train has been evaluated. In the tilting train, the overturning safety is one of the most important factors because the carbody inclines inward a curve during curve negotiation. Dynamic analysis considering unbalanced lateral acceleration and carbody tilting has been carried out and the overturning safety for the tilting train has been evaluated according to height of CG of carbody. From these studies, the overturning safety for the tilting train under unbalanced lateral acceleration of $2m/s^2$ was superior to the conventional one at the same running speed.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.10a
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• pp.220-223
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• 2004

The weight reduction of carbody structures is of great concern in developing high speed tilting train for the normal operation of tilting system. The use of composite materials for the carbody structures has many advantages due to their excellent material properties. In this paper, finite element analysis was conducted to analysis and design the composite structure of Tilting Train eXpress(TTX). According to JIS E 7105, static load tests were performed and the structural safety of the composite carbody structure was verified by conducting finite element analysis of the model to which reinforcing frame are added in the composite carbody structure. In addition, modal analysis was conducted to estimate the natural frequency of a train.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.387-392
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• 2005

Double-deck train have studied in the next generation train in KRRI. Double-deck train have more seat capacities compared with single deck vehicles and is a efficient, reliable and comfortable alternative train. Because of heavy weight, weight minimization of double-deck train carbody is imperative to reduce cost and extend life-time of train. Weight minimization problem of the double-deck train car-body is required to decide 66 design variables of thicknesses for large aluminum extruded panel while satisfying stress constraints. Design variables are too many and one execution of structural analysis of double-deck train carbody is time-consuming. Therefore, we adopt approximation technique to save computational cost of optimization process. Metamodels such as response surface model (RSM) and kriging model are used to approximate model-based optimization is described. RSM is easy to obtain and expressed explicit function, but this is not suitable for highly nonlinear and large scaled problems. Kriging model employs an interpolation scheme and is developed in the fields of spatial statistics and geostatistics. Target of this design is to find optimum thickness of AEP to minimize weight of doulbe-deck train carbody. In this study, meta model techniques are introduced to carry out weight minimization of a double-deck train car-body.