• 한국생산제조학회지
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• 제26권2호
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• pp.205-213
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• 2017

In order to improve occupant protection in frontal crash, the IIHS introduced a small overlap frontal crash test in 2012. When the front corner of a car collides with another car or object, such as utility pole the test replicated the sequence of events. Because occupants move simultaneously forward and toward the side of the vehicle this test is challenging for some airbag and safety belt designs. In the small overlap frontal test, a car travels at 64 km/h toward a rigid barrier. A hybrid III dummy is positioned in the driver seat. 25% of the total width of the car strikes the barrier on the driver side. After review of small overlap frontal test protocol and overall rating, six run-throughs were performed according to the original test method.

• 한국자동차공학회논문집
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• 제11권1호
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• pp.128-136
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• 2003

In today's design trend of vehicle structure, crush zone is fiequently reinforced by adding a box-shaped sub-frame in order to avoid an excessive deformation against a high-speed offset barrier such as EU Directive 96/97 EC, IIHS offset test. That kind of vehicle structure design results in a relatively monotonic crash pulse for airbag ECU(Electronic Control Unit) located at non-crush zone. As for an angular crash event, the measured crash signal using a single-axis accelerometer in a longitudinal direction is usually weaker than that of frontal barrier crash. Therefore, it is not so easy task to achieve a satisfactory crash discrimination performance for offset and angular crash events. In this paper, we introduce a new crash discrimination algorithm using an electronic X-Y 2-axis accelerometer in order to improve crash discrimination performance especially for those crash events. The proposed method uses a crash signal in lateral direction(Y-axis) as well as in longitudinal direction(X-axis). A crash severity measure obtained from Y-axis acceleration is used to improve the discrimination between fire and no-fire events. The result obtained by the proposed measure is logically ORed with an existing algorithm block using X-axis crash signal. Simulation and pulse injection test have been conducted to verify the performance of proposed algorithm by using real crash data of a 2,000cc passenger vehicle.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.770-775
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• 2001

Steel bar breaking system is a component of a sled test system for automobile crashworthiness. It is a recent idea for the sled test. In a sled test, a crash pulse is given as a input made from a real test. The steel bar breaking system is designed to generate a certain crash pulse. Orthogonal arrays from design of experiments (DOE) are employed. The factors of the array are panel thickness and the number of steel bars, and the levels are candidate values of them. A simulation is utilized for the crash analysis. A commercial system called LS/DYNA3D is adopted. A test system is designed based on the results.

• The Journal of Asian Finance, Economics and Business
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• 제5권4호
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• pp.67-72
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• 2018

The purpose of this study is to investigate the effect of quality of management discussion and analysis (MD&A) disclosure on stock price crash risk. The MD&A can be seen to reflect the management's intention on public announcement and reveals directly what the management says to communicate with outside investors. A firm's high-quality MD&A implies the management's commitment to communicating with the market, not allowing the managers to have incentives to hoard unfavorable news, which if revealed to the public, may lead to downward stock price corrections, damaging corporate values. The high-quality MD&A is, thus, likely to reduce the stock price crash risk. We use a logistic regression to test whether MD&A influences crash risk using listed companies in the Korean Stock Exchange (KSE) stock market between 2010 and 2013. Findings of the empirical test show that the higher the quality of MD&A, the less likely crash risk appears, implying that the MD&A disclosed adequately can be one of the factors mitigating firm's stock price crash risk. This study has implications as it presents the MD&A disclosure as a factor influencing stock price crash risk and suggests voluntary disclosure as well as mandatory disclosure acts as a variable that explains the risk of stock price crash.

• 한국자동차공학회논문집
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• 제8권6호
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• pp.259-266
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• 2000

Crash test data from different impact modes and threshold speeds were used to assess the effects of impact conditions on air bag electronic single point sensing (ESPS) activation requirements. The requirements are expressed in terms of the desired sensor activation time based on unbelted driver dummy kinematics. A crash discriminator pre-displacement is introduced to crash recognition algorithm to the ESPS. The new crash recognition algorithm named Velocity Energy Pre-displacement(VEPD) method is developed and the ESPS algorithm based on the VEPD technique is used to assess the ESPS system performance. It is shown that VEPD method correlates very well with desired sensor activation time and meets the activation requirement.

• 자동차안전학회지
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• 제14권4호
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• pp.21-26
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• 2022

Commercial use of autonomous vehicles is to come soon. So far most of responsibility of the accident is on the human driver with conventional vehicles whereas that will be on the car OEM and transportation related organizations with autonomous vehicles, which asks car OEM's and government to do vast study of car crash in various conditions. Test protocols need amendment and to be newly enacted to reflect new findings from the study aforementioned. Rigid stationary barrier and moving or stationary deformable barrier as well as car to car test which is same as actual accident can be utilized to simulate the crash happening on the road. Among those 3 test methods, rigid stationary barrier is most economic and has good repeatability. Limitation as well as advantage of the rigid stationary barrier is studied through comparison between car to car crash and oblique rigid barrier crash.

• 자동차안전학회지
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• 제9권1호
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• pp.13-18
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• 2017

In recent years, NCAP regulations of many countries have induced automaker to improve the vehicle crashworthiness. But, the current NCAP regulations don't cover all types of traffic accidents. And rapid-increasing market share of compact cars and SUVs has brought for both consumer and automaker to pay more attention on crash compatibility. So, many countries have tried to develop the new crash test mode and update the present crash test mode. Especially, Euro NCAP has been developing a new impact protocol of the car-to-car frontal offset impact including the crash compatibility assessment. There are plans to introduce this new protocol in 2020, and it will be replaced the current Euro NCAP frontal offset impact. The test dummy in the front seats of this new test mode will be changed from 50% Hybrid-III male to 50% THOR male. This paper will address the vehicle responses, the occupant responses and the vehicle compatibility performance from a full vehicle crash test using the new car-to-car frontal offset test protocol of Euro NCAP.

• 자동차안전학회지
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• 제5권1호
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• pp.11-15
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• 2013

Small overlap crash caused fatal injury in real-world crash. IIHS(Insurance Institute for Highway Safety) proposed the small overlap test. The objective of this study is to analyze dummy injury criteria and dummy excursion on the sled reinforced body angle. Result of the comparisons of dummy injury criteria of a head, neck, and chest was best correlation between sled and vehicle test on base $angle+3^{\circ}$. However, lower extremity was not correlation because sled test could not copy of intrusion. There were a correlation between dummy movement and sled reinforced body angle. Sled reinforced body angle affects the lateral direction of excursion more than longitudinal excursion.

• 한국자동차공학회논문집
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• 제15권5호
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• pp.72-77
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• 2007

Since 2000, sports utility vehicles(SUVs) occupy about 40% of domestic vehicle sales. As sports utility vehicle sales are increased the probability of crash accident between SUVs and passenger vehicles increases. Generally, SUVs are heavier than passenger vehicles and their drive height and front end stillness are higher than passenger vehicles. Because of these characteristics SUVs cause more severe injury and fatal injury in SUV to passenger vehicle head-on impact. To evaluate SUV's aggessivity to passenger vehicle, we carried out SUV to passenger vehicle head-on crash test. And finally the way how to reduce incompatibility between SUVs and passenger vehicles is suggested.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.489-494
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• 2001

This paper develops a finite element model for frontal crash analysis of a large-sized truck. It is composed of 220 parts, 70,041 nodes and 69,073 elements. This paper explains only major parts' models in detail such as frame, cab, floor, and bumper which affect on crash analysis a lot. In order to prevent penetration not only at a part itself but also between parts, all contact areas are defined using type-36, self-impact type. The developed model's reliability is validated by comparing simulation and crash test results. The results used for model validation are vehicle pulses at B-pillar, and frame and deformation of frame and cab. The frontal crash simulation is performed with the same conditions as crash test. And, it is performed using PAM-CRASH installed in super-computer SP2. The developed model whose reliability is verified may be used as a base to develop a finite element model for occupant behavior and injury coefficient analysis.