• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.12
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• pp.1070-1079
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• 2012

The impact energy absorbing is a very important characteristic of an aircraft to enhance the survivability of occupants when an aircraft is under the survivable accident such as an emergency landing condition. The impact energy is generally transmitted into the occupant and absorbed through a landing gear, a subfloor (lower structure of fuselage), and a seat. The characteristic of crash energy absorbing of a subfloor depends on the type of an aircraft, a shape of structure, and an applied material. Therefore, the study of crashworthiness characteristics of a subfloor structure is very important work to improve the safety of an aircraft. In this study, a finite element model of a narrow body fuselage section for the 80~90 seats regional aircraft was developed and crash simulation was executed using an explicit finite element analysis. Through survey of the impact energy distribution of each structural part of a fuselage and floor-level acceleration response, the crashworthiness characteristics and performance was evaluated.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.12
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• pp.182-191
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• 2004

This study is focused on the development of a child human model, which is composed of skin, skeleton, joints and muscle, etc. The dimension of child outer skin is referred to anthropometric data from KRISS (Korea Research Institute of Standards and Science). The positions of joint and mass properties of body segments are calculated from ATB(Articulated Total Body) program, GEBOD. The properties of bones and muscles are obtained by the way of scaling from adult human model. To verify the developed human model, ROM simulation and sled test is conducted. Developed human model can be effectively applied to the evaluation of human injury in crash situation and development of child restraint system. The explicit finite element program $PAM-CRASH^TM$ was used to simulate six-year old child human model.

• International Journal of Automotive Technology
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• v.5 no.3
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• pp.173-180
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• 2004

An intensive study was conducted for the crash worthy structural design of the recently developed Korean High Speed Train (KHST). Two main design concepts were set up to protect both crews and passengers from serious injury in heavy collision accidents, and to reduce damage to the train itself in light collision accidents. A collision against a movable 15-ton rigid obstacle at 110 kph was selected from train accident investigations as the accident scenario for the heavy collisions. A train-to-train collision at the relative velocity of 16 kph was used for the light collision. The crashworthiness behaviors of KHST were numerically evaluated using FEM. Analysis results using 1-D collision dynamics model of the full rake consist and 3-D shell element model of the front end structure showed good crashworthy responses in a viewpoint of structural design. Occupant analyses and sled tests demonstrated that KHST performed well enough to protect occupants under the considered accident scenarios. Finally our numerical approaches were evaluated by a real scale collision test.

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

• 연구논문집
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• s.32
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• pp.103-111
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• 2002

In this study, the crashworthiness of KHST has been evaluated by analysing a nonlinear spring/bar-damper-mass model of 1-dimensional collision dynamics. The numerical results show that KHST can easily absorb kinetic energy at lower impact force and acceleration in heavy collisions, when compared with KTX. Also, in a Light collision like a traint-to-train accident at lower speed under 8 kph, the carbody and components of KHST can be protected without any damage except the energy absorbing tube to be replaced easily. However, KTX may be much damaged in the light collision because there is no energy absorbing tube. In conclusion, the crashworthy performance of KHST has been much improved than that of KTX, although there are something to be improved for a better crashworthy performance

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.1
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• pp.89-98
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• 2007

Crashworthiness design is of special interest in automotive industry and in the transportation safety field to ensure the vehicle structural integrity and more importantly the occupant safety in the event of the crash. Front side assembly is one of the most important energy absorbing components in relating to the crashworthiness design of vehicle. The structure and shape of the front side assemblies are different depending on automakers. Thus, it is not easy to grab an insight on designer's intention when you glance at a new front side member without experiences. In this paper, we have performed the explicit nonlinear dynamic finite element analysis on the front side assembly of a passenger car to identify the mechanical roles of each part of the assembly and to enhance the absorbing energy from the viewpoint of reverse engineering.

• Journal of the korean Society of Automotive Engineers
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• v.18 no.4
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• pp.36-49
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• 1996

본 고에서는 정면충돌.측면충돌 등과 같은 각종 충돌상황시의 승객보호기준과 모델링 및 해석결과 등을 승객거동해석결과와 차체충돌해석결과를 연계하여 이를 초기설계에 이용할 수 있는 방안을 제시하고자 한다. 차체충돌해석 소프트웨어 개발에 관해서는 계속되는 글에서 설명될 것이다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.1
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• pp.1-11
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• 2020

Medium to large post structures installed along the roadside without proper protection can lead to serious vehicle damage and occupant injury at the impact. In North America and Europe, splitting systems such as slip base or breakaway device are used to reduce impacts. But the system has the risk of secondary accident when the splitted post falls down to the traffic or pedestrian. Sliding Post have been proposed as a way to solve this problem. By studying the crash test results of the 1.3ton and 0.9ton vehicle with 60 km/h and 80 km/h to a Rigidly Fixed Post (RFP) and Sliding Post (SP), danger of the conventional RFP and crashworthiness of the SP have been proven. While collision analysis only from the acceleration measured at the center of the vehicle assumes the motion of the post is the same as that of the vehicle, in this paper, by adding high speed film data to the analysis with vehicle acceleration could have separate the post motion from the vehicle motion. It gives better explanations on the movement of post and vehicle in each distinctive time step and provides basics to the crashworthy post design.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.71-76
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• 2004

To deal with ship collision or grounding, double hull structure has been applied to ships carrying dangerous cargoes. Studies about ability of double hull structure to absorb collision energy and determining fracture state are still under researching. In this study, commercial analysis code, LS-DYNA3D, is used to analyze collision strength of ships in various scenarios. 46K Chemical／Product Carrier is used as analysis subject ship. Study about Energy-Indentation and Force-Indentation is conducted under conditions that weight and collision velocity are changed. Results of this study are very helpful to make mechanism of collision accident clear and to supply useful information about collision strength criteria.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.3
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• pp.331-337
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• 2012

In this study, the front side member is optimized using a topography optimization technique. Optimization of a simple beam is conducted before optimization of the front side member. The objective function is set to minimize the first buckling factor in the longitudinal direction. The design variable corresponds to the perturbation of nodes normal to the shell's mid-plane space. The crash analysis is conducted on a simple beam, which is optimized by Response Surface Method and the topography optimization technique. In order to verify the topography optimization technique, the results of the RSM and topography optimization model are compared. Consequently, we confirm the satisfactory performance of the topography optimization technique, and apply this topography optimization to the front side member. Thus, the front side member is optimized and its crashworthiness is increased.