Papers by Keyword: Tilting Train

Abstract: The mechanical-electrical coupled dynamic model of the tilting train is established in order to study the failure effects of tilting control system. Four kinds of movement of the driving actuator are compared, specifically including: normal tilting, no tilting, insufficient tilting and tilting on the contrary. The results has shown: when the tilting is insufficient or no tilting, the influence to the dynamic is small, the curve-passing speed reduces obviously; when tilting on the contrary, the dynamic performances of front bogie become worse and the curve-passing speed decreases much more.

Abstract: In this study, the effect of combined environmental factors such as ultraviolet ray, high temperature and high moisture on mechanical and thermal analysis properties of glass fabric and phenolic composites are evaluated through a 2.5KW accelerated environmental aging tester. The environmental factors such as temperature, moisture and ultraviolet ray applied of specimens. A xenon-arc lamp is utilized for ultraviolet light and exposure time of up to 3000 hours are applied. Several types of specimens - tensile, bending, and shear specimens that are warp direction and fill direction are used to investigate the effects of environmental factors on mechanical properties of the composites. Mechanical degradations for tensile, bending and shear properties are evaluated through a Universal Testing Machine (UTM). Also, storage shear modulus, loss shear modulus and tan δ are measured as a function of exposure time through a Dynamic Mechanical Analyzer (DMA). From the experimental results, changes in material properties of glass fabric and phenolic composites are shown to be slightly degraded due to combined environmental effects.

Abstract: This paper explains the structural safety evaluation of a hybrid composite train carbody. The composite carbody with length of 23m was manufactured as a sandwich structure composed of a 40mm-thick aluminum honeycomb core and 5mm-thick woven fabric CF1263 carbon/epoxy face. In order to evaluate the structural safety of it, the dynamic force of ±0.2g was applied to the full weight carbody by two 50-ton capacity hydraulic actuators. The excitation frequency was determined by the first bending natural frequency evaluation test under full weight condition. The test was conducted for 2x106cycles. During the test, the nondestructive tests using X-ray for the composite body structure and liquid penetrant test for the welding region of the steel underframe were performed.

Abstract: The concept of light weight design will be very helpful for the tilting train to travel around a curve at a faster speed because the light weight car body makes the center of gravity lower. The impact characteristics of composite materials should be investigated because the impact property of composites is very important. This paper investigates the low-velocity impact characteristics and residual strength conducted on honeycomb sandwich panels. Low-velocity impact tests were carried out at different energy levels on honeycomb sandwich panels using a drop-weight apparatus. The impact-induced damages such as fiber breakage, matrix crack and delamination are examined with an optical microscope apparatus. Residual strength was evaluated by applying three point bending load to honeycomb sandwich panels. Experimental results show that the residual strength is greatly reduced as the impact energy increases. From the microscopic observation data, matrix crack, fiber breakage and delamination are the main impact damages of honeycomb sandwich panels.

Abstract: Recently, the use of composite material to railway vehicles is gradually increasing due to its light weight. The concept of light weight design will be very helpful for the tilting train to travel around a curve at a faster speed because the light weight car body makes the center of gravity lower. The impact characteristics of composite materials should be investigated because the impact property of composites is very important for the design and repair of a tilting train. This paper investigates the low-velocity impact and damage characteristics conducted on woven carbon/epoxy laminates for a tilting train. Low-velocity impact tests were carried out at different energy levels on woven type of laminates using a drop-weight apparatus. The impact-induced delaminations are examined by ultrasonic technique such as C-Scan. Those delaminations are also examined by laser technique such as ESPI (Electronic Speckle Pattern Interferometry). Experimental results show that the type of damage is dependent on the impact energy level and the delamination area becomes larger as the impact energy increases.

Abstract: This study has performed the experimental study to assess the structural safety of a bolster frame that is applied to the bogie system of Korean tilting train. In order to achieve this goal, firstly, loading conditions imposed on the bolster frame were investigated. Based on the international standard and dynamic analysis, the loading conditions were derived. In this study, the dynamic load cases that consider the carbody tilting effect were established. The structural safety of the bolster frame was evaluated by static test under these static loads and the fatigue strength was assessed using Goodman diagram. From the assessment, the bolster frame has satisfied the structural safety. In addition, fatigue test was carried out up to 1x107cycles under tilting load condition established in this study. The inspection of fatigue crack using NDT method was conducted at 6x106 and 1x107 cycles.

Abstract: This paper shows the experimental study to evaluate the fatigue strength of a bogie frame for Korean tilting train. The various load cases were established based on the international standard (UIC615-4) and the special tilting load case, which is unique in the tilting train, was derived by dynamic analysis and logical assumption of operation under worst tilting condition. The experimental study was conducted by means of two ways, both static and fatigue loading test. Through the static load test, the safety against fatigue was assessed using Goodman diagram of the material used. The fatigue load test was carried out up to 1x107cycles. The fatigue strength was assessed by fatigue crack inspection by means of NDT test at the stage of 6x106cycles and 1x107cycles.

Abstract: This paper has performed the fatigue strength evaluation for the bogie frame of Korean tilting train. In order to verify the structural safety of the bogie frame, we firstly investigated the loading condition imposed on the bogie frame. The bogie frame of the tilting train is exposed to the more severe loadings compared with the conventional one because of the tilting of the carbody and the high-speed curve negotiation. We have conducted some multi-body dynamic analyses to extract the load condition by tilting on curve. The finite element analysis is used to obtain the stress distribution. Through this study, we could make sure the safety of the tilting bogie frame.