• 한국자동차공학회논문집
• /
• 제8권3호
• /
• pp.163-170
• /
• 2000

Accident statistics shows that the portion of fatal occupant injuries due to side impacts is considerably high. The side impact usually leads to a severe intrusion of side structure into the passenger compartment. Furthermore, the safety zone for the side impact is relatively small compared to the front impact. Those kinds of physics for side impact frequently result in a fatal injury for the occupant. Therefore, NHTSA and EEVC are trying to intensify the regulation for the occupant protection against side impact. Both the regulation and recent market trends are asking for an installation of side airbag. There are several types of system configuration for side impact sensing. In this paper, we adopt the acceleration-based remote sensing method for the side airbag control system. We mainly focus on the development of hardware and crash discrimination algorithm of remote sensing unit. The crash discrimination algorithm needs fast decision of airbag firing especially for high-speed side impact such as FMVSS 214 and EEVC tests. It is also required to distinguish between low-speed fire and no-fire events. The algorithm should have a sufficient safety margin against any misuse situation such as hammer blow, door slam, etc. This paper introduces several firing criteria such as acceleration. velocity and energy criteria that use physical value proportional to crash severity. We have made a simulation program by using Matlab/Simulink to implement the proposed algorithm. We have conducted an algorithm calibration by using real crash data for 2,500cc vehicle. The crash performance obtained by the simulation was verified through a pulse injection method. It turned out that the results satisfied the system requirements well.

• International Journal of Automotive Technology
• /
• 제6권6호
• /
• pp.643-655
• /
• 2005

The frontal crash optimization of S-shaped closed-hat section member using the homogenization method, design of experiment (DOE) and response surface method (RSM) was studied. The optimization to effectively absorb more crash energy was studied to introduce the reinforcement design. The main focus of design was to decide the optimum size and thickness of reinforcement. In this study, the location of reinforcement was decided by homogenization method. Also, the effective size and thickness of reinforcements was studied by design of experiments and response surface method. The effects of various impact velocity for reinforcement design were researched. The high impact velocity reinforcement design showed to absorb the more crash energy than low velocities design. The effect of size and thickness of reinforcement was studied and the sensitivity of size and thickness was different according to base thickness of model. The optimum size and thickness of the reinforcement has shown a direct proportion to the thickness of base model. Also, the thicker the base model was, the effect of optimization using reinforcement was the bigger. The trend curve for effective size and thickness of reinforcement using response surface method was obtained. The predicted size and thickness of reinforcement by RSM were compared with results of DOE. The results of a specific dynamic mean crushing loads for the predicted design by RSM were shown the small difference with the predicted results by RSM and DOE. These trend curves can be used as a basic guideline to find the optimum reinforcement design for S-shaped member.

• 한국산학기술학회논문지
• /
• 제22권1호
• /
• pp.402-408
• /
• 2021

기계 설계를 기반으로 제작한 자동차에 의한 사고 발생 시 차량 공학적인 분석은 심도 있게 조사하지 않고 조사자의 주관적인 경험 지식을 토대로 분석하는 경우가 있다. 본 연구는 실제 발생한 중앙선 침범 사고 자료를 토대로 캐드(CAD) 프로그램을 이용하여 현장 상황을 도면화하고, 도면화 한 자료를 시뮬레이션 프로그램(PC-Crash)에 적용하여 250번의 충돌 상황을 반복적으로 수행하여 최종 정지 위치 및 최종 정지 자세와 부합하는 충돌 속도, 진행 자세, 조향 작동 여부 및 제동 여부 등의 상관 관계를 분석했다. 충돌 속도가 낮을수록 이탈각의 영향을 크게 받지 않고 속도가 높은 차량의 속도에 영향을 크게 받고 충돌 이후에는 유효 충돌 속도와 같이 속도가 낮은 차량은 높아지고, 속도가 높은 차량은 낮아진다. 본 연구의 시뮬레이션 결과는 마이티가 중앙선을 넘은 자세로 오르막 좌커브 구간을 진행하다가 마주오던 포터를 인지하고 자기 진행 차로로 복귀하는 과정과 포터의 전면 좌측면이 충돌하여 포터가 우대각선 방향으로 밀려나 전면이 약 11시 방향을 향해 최종 정지하는 것을 규명하였다.

• 소성∙가공
• /
• 제15권8호
• /
• pp.556-561
• /
• 2006

Most of auto-body members are composed of stamping parts. These parts have the non-uniform thickness and plastic work hardening distribution during the forming process. This paper is concerned with the side impact analysis of the ULSAB-AVC model according to the US-SINCAP in order to compare the crashworthiness between the model with and without considering the forming effect. The forming effect is ca]ciliated by one-step forming analysis for several members. The crashworthiness is investigated by comparing the deformed shape of the cabin room the energy absorption characteristics and the intrusion velocity of a car. The result of the crash analysis demonstrates that the crash mode, the load-carrying capacity and energy absorption can be affected by the forming effect. It is noted that the design of an autobody should be carried out considering the forming effect for accurate assessment of crashworthiness.

• Nuclear Engineering and Technology
• /
• 제48권2호
• /
• pp.505-517
• /
• 2016

The structural integrity of a dual-purpose metal cask currently under development by the Korea Radioactive Waste Agency (KORAD) was evaluated, through numerical simulations and a model test, under high-speed missile impact reflecting targeted aircraft crash conditions. The impact conditions were carefully chosen through a survey on accident cases and recommendations from literature. In the impact scenario, a missile flying horizontally hits the top side of the cask, which is freestanding on a concrete pad, with a velocity of 150 m/s. A simplified missile simulating a commercial aircraft engine was designed from an impact loade-time function available in literature. In the analyses, the dynamic behavior of the metal cask and the integrity of the containment boundary were assessed. The simulation results were compared with the test results for a 1:3 scale model. Although the dynamic behavior of the cask in the model test did not match exactly with the prediction from the numerical simulation, other structural responses, such as the acceleration and strain history during the impact, showed very good agreement. Moreover, the containment function of the cask survived the missile impact as expected from the numerical simulation. Thus, the procedure and methodology adopted in the structural numerical analyses were successfully validated.

• 자동차안전학회지
• /
• 제9권3호
• /
• pp.7-12
• /
• 2017

The whiplash is the most important issue of low speed rear-impact. So auto makers are committed to developing a seat to improve whiplash injury. Most NCAP tests have been used by same pulse (Mid Velocity 16kph). Only Euro NCAP uses different pulse that consists of Low, Mid, High velocity. But Euro NCAP also uses same pulse in Mid velocity as other NCAP test. That Mid velocity NCAP pulse was made by rear impact that has 90's vehicle structure properties. That pulse was used until now days. However these days, auto maker use more high tensile steel than 90's as customer and society demand more fuel efficiency and light vehicle with good safety structure. So modern vehicles have different pulse patterns of rear impact than NCAP pulse and 90's vehicle crash properties. In this paper, the test was conducted by following condition. Target car was impacted by the rigid barrier with certain velocity. Finally target vehicle gained delta V 16kph which was same velocity as NCAP Mid Velocity pulse. It is critical velocity which occur long period neck injury. It is very different pulse that was gained by real car impact from NCAP pulse. And it has higher peak G with high fluctuation and short duration than NCAP pulse.

• 한국정밀공학회지
• /
• 제17권5호
• /
• pp.195-201
• /
• 2000

The fundamental spot welded sections of automobiles (hat-shaped and double hat-shaped sections) absorb most of the energy in a front impact collision. The sections of various thickness, shape and weld width on the flange lave been tested on axial impact crush load (Mass 40kg, Velocity 7.19m/sec) using a vertical air pressure crash est device Characteristics of impact collapse have been reviewed and a structure of optimal energy absorbing capacity is suggested.

• 자동차안전학회지
• /
• 제6권2호
• /
• pp.55-60
• /
• 2014

To verify the performance of roadside safety facilities, strength and occupant protection test are performed by evaluation criteria. Strength test use a truck and occupant protection test use a sedan. Strength perfomance is analyzed pass rate by post lateral resistance of the safety barrier. Occupant protection performance is analyzed from THIV(Theoretical Head Impact Velocity) and PHD(Post-impact Head Deceleration) by crash cushion test.

• 항공우주시스템공학회지
• /
• 제7권2호
• /
• pp.35-41
• /
• 2013

Crashworthiness design concept in the helicopter development is still under evolutionary stage. Survivability in the event of a crash was remarkably improved and this fact can be recognized by the analysis results on the AH-64 Apache and UH-60 Black Hawk crash accidents. Those two models are the first ones in which the crashworthiness design concept was applied with a full-scale requirement. Here we need to notice that under-design of the system results in unexpected injuries and deaths while over-design of the crashworthy elements result in unnecessary weight and costs. If landing gear system would be verified to have enough energy absorption capability in the specified vertical velocity interval, then design requirements of the airframe, fuel system and seats could be modified positively. In this paper, the right and systematic crashworthiness design concept is reviewed on the assumption that design requirements of some crashworthy elements could be partially tailored.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2007년도 추계학술대회 논문집
• /
• pp.21-24
• /
• 2007

This paper deals with introduction of testing equipments for the evaluation of dynamic tensile characteristics of auto-body steel sheets and the crashworthiness of auto-body members. The servo-hydraulic high speed material testing machine was developed for tensile tests at the intermediate strain rate to obtain the tensile material properties at the strain rate under 500/sec. The split Hopkinson bar apparatus using the elastic wave was developed for dynamic material characteristics at the high strain rate ranged from 1,000 to 10,000/sec. The servo-hydraulic high speed crash testing machine is the equipment for the evaluation of the collapse load and crashworthiness of auto-body members. High speed carrying truck crashes to specimen with the maximum velocity of 17 m/sec.