• Journal of the Korean Society for Railway
• /
• v.2 no.1
• /
• pp.16-27
• /
• 1999

The purpose of this study is to suggest the effective analytical procedure using finite element model for the crashworthiness of motorized trailer of high speed train. The static crush of rectangular section frame is analyzed by experiment and numerical simulation. The equivalent thickness distribution of the aluminum frame ensuring the same energy absorption as the steel frame is obtained. In the analysis of end-on collision of TGV-K, deformed pattern and section forces are obtained, and the effect of crushable zone are examined. The numerical results are applied to the design of motorized trailer of Korean high speed train.

• Journal of the Korean Society for Railway
• /
• v.1 no.1 s.1
• /
• pp.1-9
• /
• 1998

Described in this paper is the result of a study on collision analysis of TGV-K using 1-dimensional model for crashworthy design. Crashworthy design of the front end is very important because majority of the impact energy (more than 70%) is absorbed by the crush of the front end when the train is collided with an obstacle like a tank lorry. Guideline for the crashworthy design can be described from the collision analysis of the whole train using a 1-dimensional model. Since the headstock of TGV-K is not designed in a crashworthy point of view, a conceptual design of the headstock to improve crashworthiness is suggested and evaluated using 1-dimensional collision analysis. The suggested design, which adopts an energy absorber and a crashworthy headstock, shows a good behaviour on the accident scenario of SNCF (collision at 110 km/h against a movable rigid mass of 15 ton).

• Proceedings of the KSR Conference
• /
• 2008.06a
• /
• pp.2040-2045
• /
• 2008

The priority of Crashworthiness concept for rolling stock is progressively increasing to reduce the damage of drivers and passengers as well as the car. For the first step of this research, the analysis of the crash elements have been performed. Also the longitudinal collapse force and mode is important point for whole carbody structure to guarantee the lower force at end part rather than the main passenger area. The carbody quasi-static collapse analysis and real test has been performed in the research. The crash elements FEA and test has been performed as well. After the initial Analysis and test, the correlation analysis between the FEA and test has been performed by FEA tunning. All this result will be used for real crashworthiness design for carbody structure.

• Proceedings of the KSR Conference
• /
• 1998.05a
• /
• pp.361-368
• /
• 1998

Described in this paper is the result of a study on collision analysis of TGV-K using 1-dimensional model for crashworthy design. Crashworthy design of the front end is very important because majority of the impact energy (more than 70%) is absorbed by the crush of the front end when the train is collided with an obstacle like a tank lorry. Guideline for the crashworthy design can be described from the collision analysis of the whole train using a 1-dimensional model. Since the headstock of TGV-K is not designed in a crashworthy point of view, a conceptual design of the headstock to improve crashworthiness is suggested and evaluated using 1-dimensional collision analysis. The suggested design, which adopts an energy absorber and a crashworthy headstock, shows a good behaviour on the accident scenario of SNCF (collision at 110 km/hr against a movable rigid mass of 15 ton).

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.3 no.3
• /
• pp.107-116
• /
• 1983

This paper is concerned with the permeability through a decomposed granite soil layer which is influnced by change of grain sizes and crushed soils made by varied compaction energy. The change in the content of crushed soils can be described in terms of the ratio of surface area ($S_w{^{\prime}}/S_w $). The experiments were carried out to obtain the relationships of the coefficient of permeability(K) versus the optimum moisture content($w_{opt}$) by the variable head permeability test with the samples that were preapared by compaction test. The results are found as follows; (1) By the change in compaction energy, the crush ratio increased whereas the void ratio decreased with a larger maximum dry density running in parallel with the zero air void curve. (2) The ratio of surface area was $0.33(P)^{0.96}$ in $S_w{^{\prime}}/S_w $ with no relation to the compaction energy. (3) The grain size which produced the largest crush of soil particles ranged from 0.5 to 1 millimetre (4) The relationship of K versus $e^3$/1+e appeared as a straight line on the full-log-scale paper under the optimum moisture state. (5) As the compaction energy was larger, the passing percentage of #200-sieve grains increased linearly. The increment in the surface area ratio was deemed to have been caused by the decreased in the permeability.

• Clean Technology
• /
• v.25 no.4
• /
• pp.289-295
• /
• 2019

Though the usage of vinyls and plastics produced from fossil fuels has been increasing in the world, the eco-friendly domestic disposal or recycling of waste vinyls has to be executed because the migration or importation of waste vinyls or waste plastics are globally prohibited. Even though the eco-friendly domestic disposal or recycling of waste vinyls and waste plastics should be developed, promising eco-friendly recycling methods are few because there are extraneous substances in waste vinyls and waste plastics. Also, conventional incineration and landfill methods result in secondary contamination and then increase disposal costs. Therefore, the selective elimination of extraneous substances or other materials included in waste vinyls and waste plastics could make valuable recycling or reuse possible. In particular, the novel hybrid process in which crushing and screening are simultaneously conducted in a rotary kiln type reactor can domestically maximize the material recycling or reuse. In this study, the feasibility study for a crushing/screening hybrid process developed in Korea was performed and evaluated in case of thermal recycling (TR) and material recycling (MR). The effect of various subsidies on economic efficiency was especially evaluated by means of domestic recycling plans. The incentive revenues from waste vinyl recycling and the incineration share of waste vinyls affected the net present values and internal rate of returns of the hybrid process.

• Journal of Korean Society of Transportation
• /
• v.18 no.4
• /
• pp.107-115
• /
• 2000

We suggest a method which solves the planar, two vehicle collision reconstruction problem. The method based on the Principle of impulse and momentum determines the pre-impact velocity components from Post-impact velocity components, vehicle Physical data and collision geometry. A novel feature is that although the impact coefficients such as the restitution coefficient and the impulse ratio are unknown, the method can estimate automatically the coefficients and calculate the pre-impact velocity components. This reverse calculation is important for vehicle accident reconstruction, since the pre-impact velocities are unknown and Post-impact Phase is the starting Point in a usual collision analysis. However. an inverse solution is not always Possible with the analytical rigid-body impact model. Mathematically, one does not exist under the common velocity condition. On the other hand, our method has a capability of reverse calculation under the condition if the absorbed energy during the collision process can be estimated using the crush profile. To validate the developed collision reconstruction a1gorithm, we use car-to-car collision test results. The analysis and experimental results agree well in the impact coefficients and the Pre-impact velocity components.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2007.05a
• /
• pp.326-330
• /
• 2007

Bumper back beam is one of the essential structural components of front-end module. It should be designed to withstand a minor bump in low-speed collision, 2.5 mph crash test for example. And weight reduction is always important problem in the design of almost all the parts in car for energy saving. So, the key issues in shape design of a bumper are weight reduction and the performance in 2.5mph crash test. In this study, a light weight and high performance bumper back beam model was developed using analytical approach based on mechanics and FE simulation together.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.318-321
• /
• 2005

Crashworthy design of a train is a systematic approach to ensure the safety of passengers and crews in railway transportation for the prescribed accident scenarios. This approach needs new structural arrangements and designs to absorb higher levels of impact energy in a controlled manner and interior designs to minimize passenger injuries. In this paper, an evaluation method for crashworthiness of Korean tilting train express is introduced. Crush characteristics for each part of tilting train express are evaluated numerically through 3-dimensional shell element analysis with LS-DYNA. Based on a head-on collision and a level crossing collision scenarios, the crash behaviors of tilting train express are evaluated numerically using full-rake collision simulations.

• Journal of the Korean Society for Railway
• /
• v.5 no.4
• /
• pp.231-236
• /
• 2002

Todays, crash safety requirements of the railway vehicle structures become important design criterion according to the increased driving speed and the lightweight construction. Although the crash analysis using computer simulation can be effectively applied to predict the crash performance of the railway vehicles in the early design stage, the optimized design w.r.t the crash safety could be realized by the crash tests with actual prototype vehicles. However, it is very expensive and time-consuming task to perform the crash test of the railway vehicles. As a measure to cope with the problem, in this paper, the scale modeling technique is suggested and experimentally verified to predict the impact energy absorption characteristics of full scale model of aluminum extrusions sub-structures and the high-speed railway vehicle structure.