• 자동차안전학회지
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• 제6권1호
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• pp.22-26
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• 2014

Fatality of accidents on curved roads where rollover accidents are likely to take place was higher than that on straight roads. We ought to investigate factors affecting injury severity of occupant in a vehicle rollover accident. From January 2011 to December 2013, we collected data about rollover motor vehicle crash accident. We surveyed occupant's injury, vehicle type, safety devices, type of rollover accident and the number of turn in accident. Of the 132 subjects, 56.1% were males, 50.8% were drivers, 48.5% fastened seat belt, and air bag deployed in 12.1%. Among injuries sustained head, chest and abdomen were major sites of severe injury(Abbreviated injury scale>2). Seat belt use, rollover type, and the number of 1/4 turn were found to have significant positive correlations with Injury Severity Score. The regression analysis herein found significance in safety belt use and the number of 1/4 turn. Seat belt use was a significant factor affecting injury severe of occupant in rollover accident.

• Structural Engineering and Mechanics
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• 제52권6호
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• pp.1085-1098
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• 2014

Plastic mechanism analysis of structures subjected to large deformation has long been used in order to determine collapse mechanisms of steel structures, and the energy absorbed in plastic deformation during such collapses. In this paper the technique is applied to vehicle roof structures that undergo large plastic deformation as a result of rollover crashes. The components of such roof structures are typically steel spot-welded hat-type sections. Ten different deformation mechanisms are defined from investigations of real-world rollover crashes, and an analytical technique to determine the plastic collapse load and energy absorption of such mechanisms is determined. The procedure is presented in a generic manner, such that it may be applied to any vehicle structure undergoing a rollover induced collapse. The procedure is applied to an exemplar vehicle, in order to demonstrate its application in determining the energy absorbed in the deformation of the identified collapse mechanisms. The procedure will be useful to forensic crash reconstructionists, in order to accurately determine the initial travel velocity of a vehicle that has undergone a rollover and for which the post-crash vehicle deformation is known. It may also be used to perform analytical studies of the collapse resistance of vehicle roof structures for optimisation purposes, which is also demonstrated with an analysis of the effect of varying the geometric and material properties of the roof structure components of the exemplar vehicle.

• 자동차안전학회지
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• 제12권4호
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• pp.54-60
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• 2020

In a previous study, an investigation of occupant behaviors and injuries (to the head and chest) was performed during vehicle impact loading cases in order to ensure the safety of wheelchair passengers on a bus. The computational results showed overall safety tolerances of wheelchair occupants under different accident configurations. The bus crashworthiness is described as the capability of a bus to protect occupants during rollover loadings. The residual space containing occupants should be undamaged without any intrusions. However it is necessary to evaluate the residual space according to the bus occupant kinematic analysis under the rollover crash simulation. This study focuses on the evaluation of occupant behaviors during rollover loading cases in order to ensure the safety of bus passengers sitting in general seats and wheelchairs and evaluates the residual space of the bus by analyzing the bus occupant kinematics.

• 한국자동차공학회논문집
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• 제7권7호
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• pp.195-201
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• 1999

In Rollover crashes, the development of bus structure to ensure the maintenance of survival space for passengers is very important . So, this paper focuses on understanding the possibility of efficient structural development considering rollover strength through computer simulation using the commercial code, LS-DYNA3D at the initial stage of vehicle development structural members, and impact boundary conditions required by ADR59(Australian Design Rule 59)were applied. In order to confirm the validity of the computational results, the test results. After the usefulness of this method of analysis was confirmed , we have proposed the effective modificationfor rollover strength.

• 대한기계학회논문집A
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• 제38권4호
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• pp.385-391
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• 2014

차륜형전투차량은 보병부대의 전투력 강화와 기동성 향상을 목적으로 운용하는 군용차량이다. 전투차량은 운용 특성상 험난한 지형의 주행이 불가피하고 높은 무게 중심으로 인해 전복 사고의 위험성이 크다. 이러한 이유로 전투차량의 내부는 전복 사고에 따른 승무원의 안전성을 고려하여 설계해야 할 필요가 있다. 하지만 실제 차량을 이용한 시험은 현실적으로 많은 어려움이 있다. 따라서 본 연구에서는 차륜형전투차량의 전복 시험을 모사하여 승무원의 안전성을 측정하기 위한 컴퓨터 시뮬레이션 및 모델링 방법에 관한 연구를 수행한다. 본 논문의 연구 범위는 전투차량 전복 시험 조건, 전투차량 유한요소 모델링, 유한요소 인체 더미의 적용 방법, 전복 시험 시뮬레이션, 시뮬레이션 적용 시 발생 가능한 문제와 해결 방안 제시, 인체 상해치 계산 및 평가를 포함한다.

• 한국인터넷방송통신학회논문지
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• 제18권2호
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• pp.227-235
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• 2018

최근 자동차 교통량의 증가로 인해 차량 전복사고가 급증하여 이에 따른 인명피해가 증가해왔으며, 이를 방지하기 위한 차량충돌 실험장비 및 해석프로그램 개발 등의 다양한 기술이 진보되고 있다. 본 연구에서는 적용한 차량모델은 미국 FORD사의 EXPLORER 차종이고, Rollover 해석은 차량충돌해석에 상용되고 있는 PC-Crash 프로그램을 이용하여 SUV의 전복사고 거동 및 충돌속도를 예측하였다. 그 해석결과로 FMVSS No. 208 법규를 통한 SUV차량의 실제 Rollover 거동과 비교할 때 유사한 결과를 보여주었으며, 충돌속도 및 롤각의 특성은 1000 msec 이후부터는 다소 오차율이 커지는 경향을 나타냈다. 그리고 NHTSA의 데이터베이스를 활용하여 고찰한 결과로 충돌속도 15~77 km/h, 충돌각도 $22{\sim}74^{\circ}$ 범위에서 전복사고가 가장 많이 발생함을 나타냈고, 실제 사고사례를 적용함으로써 차량 출발 위치, Roof 파손위치, 정지위치를 재현시켜 차량 Roof가 파손될 때 차량속도 및 충돌시간을 예측할 수 있었다.

• 대한기계학회논문집A
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• 제28권7호
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• pp.992-998
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• 2004

During the tube hydropiercing, the region adjacent to the pierced hole will be deformed and will be drawn away from the die block as the punch advances through the wall of the tube. The deformation in the region may range from a substantially flat form to a countersunk form, so called rollover. In this study, the effects of material properties, shape of piercing punches, roundness of tube surface and internal pressure within the tube during piercing on the rollover have been investigated experimentally. The results provide the quantitative variation of rollover at given hydropiercing parameters, and a relationship between the deformed radius and the rollover caused by the deformation has been established.

• 자동차안전학회지
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• 제12권1호
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• pp.39-45
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• 2020

The express/intercity bus models have been developing for wheelchair users to provide the preferable long-distance travels by the Korean government research. In the previous studies, evaluation method was set up for the wheelchair users' safety and the study for wheelchair occupants' safety was performed under various crash loadings mimic to real accidents, frontal crash, side impact and rollover, etc. This study was focused on the evaluation of occupant behaviors and injuries (head and chest) during vehicle impact loading cases in order to ensure the safety of wheelchair passengers in the bus. The occupant response and belt loading data during the sled FE simulation were compared with those of the sled test. The simulation results showed overall safety tolerances of wheelchair occupants under the severe frontal deceleration, side impact loading based on the FMVSS 214 configuration and bus rollover loading.

• 소성∙가공
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• 제20권3호
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• pp.214-221
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• 2011

In recent years, automotive seat components have been manufactured by the fine blanking process, allowing an improvement of dimensional accuracy at sheared surface in series production. However, the rollover has increased and die failures have occurred more frequently when manufacturing gears by fine blanking. Consequently, important goals for manufacturing seat recliner parts with gears have been to decrease the rollover as well as to improve the tool life. In this study, the half blanking and shaving processes were introduced to improve aforementioned problems for the lower tooth, the main component of a seat recliner. For this purpose, the half blanking process was optimized using the finite element (FE) analysis and design of experiment (DOE). The optimized conditions resulting from this study were an offset of 0.2 mm, a clearance of 0.1 mm and a penetration depth of 4.5 mm. Fine blanking experiment conducted under the optimal condition resulted in a rollover depth decrease from 1.9 to 1.3 mm, and no die failure occurrence.

• 한국자동차공학회논문집
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• 제15권1호
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• pp.56-63
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• 2007

In case of bus rollover, the body structure of the bus should be designed to ensure the survival space for passengers. So, this study focuses on evaluating rollover strength through a computer simulation using the commercial code, LS-DYNA3D at the initial stage of vehicle development. For this study, section structure was modeled using a simple beam element, and impact boundary conditions required by ECE(Economic Commission for Europe) regulation No.66 were applied. In order to confirm the validity of the beam element bus model, the results compared with the test results and shell element bus model. The analysis errors from beam element bus model are due to the difference in strain energy of joint area between beam and shell model. In this study, a method for the joint modeling was suggested by using nonlinear springs to which the collapse mechanisms were applied.