• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 춘계학술대회 논문집
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• pp.686-693
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• 2003

An intensive study was conducted for crashworthiness structural design of recently developed Korean High Speed Train. Two nam design concepts are setup to protect the both crews and passengers from serious injury at heavy collision accidents, and to reduce damages of the train itself at light collision accidents. For occupant protection a collision against a movable 15 tons rigid obstacle at 110 kph and a train-to-train collision at 30 kph were selected as accident scenarios for the heavy collisions based on the train accident investigations. A train-to-train collision at 8 kph was used for the light collisions. The crashworthiness behaviors of KHST have been evaluated numerically using the finite element method. Also, one-dimensional collision analyses show good crashworthy responses in a full rake consist and 3-dimensional shell element analyses do in the front-end structures of the power car. Occupant analyses and sled tests demonstrated that KHST performs well enough to protect occupants under the considered accident scenarios.

• 자동차안전학회지
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• 제3권2호
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• pp.5-10
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• 2011

Under the full frontal crash event, seatbelt system is the most typical and primary restraint device that prevents the second impact between an occupant and vehicle interior parts by limiting the forward motion of an occupant in the vehicle occupant packaging space. Today's restraint systems typically include the three-point seat belt with the pretensioner and the load limiter. A pretensioner preemptively tightens the seat belts removing any slack between a passenger and belt webbing which leads to early restraint of a passenger. After that a load limiter controls level of belt load by releasing the belt webbing to reduce occupant injurys. In this study, load characteristics of load limiters are optimized by the computer simulation with a MADYMO model for a frontal impact against the rigid wall at 56kph and then we suggest performance requirements. We derived optimum load characteristic from the results using four vehicle simulation models represented by the vehicle. Based on the results, we suggest the performance from the results of the second optimization using the simulation considering the design and the standardization. Finally, the performance requirements is verified by the sled tests including the load limiter device for the full vehicle condition.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1995년도 추계학술대회논문집
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• pp.91-100
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• 1995

자동차의 안전도는 전통적으로 정면 충돌시 승객의 보호 정도를 가지고 비 교 된다. 그러나 근래에 와서는 다양한 사고에 의한 승객의 피해를 볼 때 정면 과 더불어 측면 충돌시의 피해를 무시할 수 없는 상태에 이르렀다. sled tests 등을 통해서 정면 뿐만 아니라 측면 충돌의 영향도 파악하고 있으나 정면 충돌보다 측면 충돌에 대해 승개 보호 장치의 개발이 미흡한 것이 현실이다. 본 연구에서는 현실적으로 보다 효과적인 occupant (운전자 및 승객) restraint system을 computer 모의 실험을 통해서 제안하고자 하였다. 기존의 안전시스템인 lap/shoulder belt system과 Air cushion에 의한 실험은 다각도로 연구되었다. 그러나 측면 충돌에서 Air Bag에 의한 충돌 감소 영향은 정면 충돌에 비해 적어지게 되어 상체 측면 보호 장치가 필요하게 된다. 본 연구에서는 운전자의 lap/shoulder belt system과 Air Bag에 의해 구속되는 dummy를 가지고 다양한 측면 충돌 각도 (0 .deg. , 15 .deg. , 30 .deg. , 45 .deg. , 70 .deg. )에서 실험이 수행되었다. 또한 각 충돌각에 대해 기존 Restraint System에 상체 측면 보호 장치(seat wing)를 포함하여 실험을 수행 하였다. 이에 대한 각각의 영향, 그리고 승객 손상도 분석 및 평가를 통하여 보안된 측면 충돌 보호 restraint system의 필요성과 그 효과를 제시하고자 한다. 실험결과 에 의하면 정면보다 측면에서 충돌하였을 경우 보조 구속 시스템인 seat wing으로 인 해 측면보호는 물론 occupant는 정면으로 나가게 개선되어 구속 시스템으로써의 이점이 확대되고 shoulder blet 또는 dummy의 감속을 통제하는 Air Bag의 잠재적인 이점이 더욱 확대되었음을 보여주고 있다. 그러나 design 단계에서 편안함, 안락감 등의 문제들과, 다른 실용적인 면에 대한 계속적인 연구가 필요하다.

• International Journal of Automotive Technology
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• 제8권2호
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• pp.185-191
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• 2007

The new FMVSS 208, 213, 225 regulations include automatic suppression of airbags to prevent low-risk airbag deployment and the use of child seats with a rigid-bar anchor system. The regulations mean that children must sit in the rear seat, but do not include other specific safety measures for their protection. In the rear, restraint equipment consists of three-point shoulder/lap belts for the outside seats and a static two-point lap belt in the middle, with no additional devices such as pretensioners or load limiters; this is far from optimal for children. This study investigated injury rates using a 3-year-old-child dummy. ECE R44 sled tests used a booster, a speed of 48 km/h, and a 26- to 32-g rectangular deceleration pulse. While seated on a booster, the dummies were restrained by an adult shoulder/lap three-point belt. HIC_15 msec, Chest G and Nij were somewhat lower with an emergency locking retractor (ELR)+pretensioner+load limiter than with only an ELR or with ELR+pretensioner. However, the current seat-belt system results in injury rates that exceed the limit for OOP performance under the new FMVSS 208 regulations.

• Journal of Mechanical Science and Technology
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• 제15권7호
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• pp.1072-1076
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• 2001

A biomechanical study was conducted in this study to investigate if in-line skating wrist guards can effectively reduce the impact forces so as to protect the wrist from fracture. The forearm specimens with and without wrist guards were dropped using a specially designed sled to simulate the impact on the wrist while falling. A force plate was used to measure the total impact force on the dropping weight whereas a load cell was attached to the proximal end of the specimen and used to quantify the impact transmitted through the wrist joint. From the non-destructive tests, mean peak force measured from a force plate showed no difference between the guarded and unguarded groups whereas mean impulse of the guarded group was significantly greater than that of the unguarded group (p<0.01). Comparing the peak force and impulse measured from the load cell, the peak force of the guarded group was significantly less than that of the unguarded group (p<0.001), while the impulse values were similar. When the specimens were dropped from a higher position (2.5ft ve. 1ft), all unguarded specimens had severe wrist fractures whereas fracture was found in three out of 5 guarded specimens. Comparison of mean peak forces and impulses showed as significant difference between the guarded and unguarded groups only in the mean impulse measured from the force plate. These results suggest that the wrist guard may protect the wrist by attenuating the peak force transmitted to radius and ulnar although it may not be effective when the wrist is subjected to an impact sufficiently large to cause fractures.

• 대한기계학회논문집A
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• 제35권10호
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• pp.1187-1191
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• 2011

이 응용논문에는 적응형 로드리미터에 대해 기술되어 있다. 적응형 로드리미터는 안전벨트의 구성품 중 하나이며, 이는 승객의 다양한 체중과 키에 따라 하중량을 고하중과 저하중으로 변환시킬 수 있는 장치이다. 최근, FMVSS 208규정은 다양한 더미크기에 대해 엄격한 안전기준을 요구하고 있다. 이에 따라 우리는 고하중 조건과 저하중 조건 시 각각 더미에 흉부 상해정도를 알아보았고, 실험을 통해서 벤치마킹모델의 하중조건을 확인하였다. 이를 토대로 적응형 듀얼레벨 로드리미터를 개발하여 성능 실험을 실시하였고, 유한요소해석을 통해 설계 개선점을 확인하였다.

• Nuclear Engineering and Technology
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• 제53권9호
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• pp.3068-3084
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• 2021

Investigations of large commercial aircraft impact effect on nuclear power plant (NPP) buildings have been drawing extensive attentions, particularly after the 9/11 event, and this paper aims to experimentally assess the damage and vibrations of NPP buildings subjected to aircraft crash. In present Part I, two shots of reduce-scaled model test of aircraft impacting on NPP building were carried out. Firstly, the 1:15 aircraft model (weighs 135 kg) and RC NPP model (weighs about 70 t) are designed and prepared. Then, based on the large rocket sled loading test platform, the aircraft models were accelerated to impact perpendicularly on the two sides of NPP model, i.e., containment and auxiliary buildings, with a velocity of about 170 m/s. The strain-time histories of rebars within the impact area and acceleration-time histories of each floor of NPP model are derived from the pre-arranged twenty-one strain gauges and twenty tri-axial accelerometers, and the whole impact processes were recorded by three high-speed cameras. The local penetration and perforation failure modes occurred respectively in the collision scenarios of containment and auxiliary buildings, and some suggestions for the NPP design are given. The maximum acceleration in the 1:15 scaled tests is 1785.73 g, and thus the corresponding maximum resultant acceleration in a prototype impact might be about 119 g, which poses a potential threat to the nuclear equipment. Furthermore, it was found that the nonlinear decrease of vibrations along the height was well reflected by the variations of both the maximum resultant vibrations and Cumulative Absolute Velocity (CAV). The present experimental work on the damage and dynamic responses of NPP structure under aircraft impact is firstly presented, which could provide a benchmark basis for further safety assessments of prototype NPP structure as well as inner systems and components against aircraft crash.