• Title, Summary, Keyword: Crash Analysis

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Development of Al Crash Box for High Crashworthiness Enhancement (고충돌에너지 흡수용 알루미늄 크래쉬박스 개발)

  • Yoo, J.S.;Kim, S.B.;Lee, M.Y.;Huh, H.
    • Transactions of Materials Processing
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    • v.17 no.3
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    • pp.182-188
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    • 2008
  • Crash box is one of the most important automotive parts for crash energy absorption and is equipped at the front end of the front side member. The specific characteristics of aluminum alloys offer the possibility to design cost-effective lightweight structures with high stiffness and excellent crash energy absorption potential. This study deals with crashworthiness of aluminum crash box for an auto-body with the various types of cross section. For aluminum alloys, A17003-T7 and A17003-T5, the dynamic tensile test was carried out to apply for crash analysis at the range of strain from 0.003/sec to 200/sec. The crash analysis and the crash test were carried out for three cross sections of rectangle, hexagon and octagon. The analysis results show that the octagon cross section shape with A17003-T5 has higher crashworthiness than other cross section shapes. The effect of rib shapes in the cross section is important factor in crash analysis. Finally, new configuration of crash box with high crash energy absorption was suggested.

Steel processing effects on crash performance of vehicle safety related applications

  • Doruk, Emre
    • Steel and Composite Structures
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    • v.24 no.3
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    • pp.351-358
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    • 2017
  • Due to the increasing competition, automotive manufacturers have to manufacture highly safe and light vehicles. The parts which make up the body of the vehicle and absorb the energy in case of a crash, are usually manufactured with sheet metal forming methods such as deep drawing, bending, trimming and spinning. The part may get thinner, thicker, folded, teared, wrinkled and spring back based on the manufacturing conditions during manufacturing and the type of application methods. Transferring these effects which originate from the forming process to the crash simulations that are performed for vehicle safety simulations, makes accurate and reliable results possible. As a part of this study, firstly, the one-step and incremental sheet metal forming analysis (deep drawing + trimming + spring back) of vehicle front bumper beam and crash boxes were conducted. Then, crash performances for cases with and without the effects of sheet metal forming were assessed in the crash analysis of vehicle front bumper beam and crash box. It was detected that the parts absorbed 12.89% more energy in total in cases where the effect of the forming process was included. It was revealed that forming history has a significant effect on the crash performance of the vehicle parts.

Reliability Evaluation of EDR Data Using PC-Crash & Vbox (Vbox와 PC-Crash를 활용한 EDR 기록정보의 신뢰성 평가)

  • Park, Jongchan;Kim, Jonghyuk;Oh, Wontaek;Choi, Jihun;Park, Jongjin
    • Transactions of the Korean Society of Automotive Engineers
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    • v.25 no.3
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    • pp.317-325
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    • 2017
  • The EDR(Event Data Recorder) is a part of the ACU(Airbag Control Unit) functions mounted on a vehicle. EDR data have pre-crash data and post-crash data. Pre-crash data are recorded within 5 sec from time zero(AE) with 0.5 sec resolution, and reveal vehicle speed, engine rotation speed, throttle opening, brake pedal operation, acceleration pedal position and steering angle, etc. Using this EDR data, the investigation of a traffic accident can become more objective and scientific. Crash tests of three vehicles equipped with EDR function had been performed successfully. Evaluation of EDR data reliability had also been performed using Vbox and PC-Crash's sequence table function. Based on the results, we could confirm EDR data's reliability and availability for Traffic Accident Analysis by the series of this process.

Development of an Automobile Black Box for Reconstruction Analysis of Collision Accidents (충돌사고 재구성 해석을 위한 차량 블랙박스의 개발)

  • 이원희;한인환
    • Transactions of the Korean Society of Automotive Engineers
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    • v.12 no.2
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    • pp.205-214
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    • 2004
  • This paper presents design concepts, specifications and performances of a newly developed Black Box, the reconstruction analysis tool with the records, and results of validation tests. The Black Box can detect crash accidents automatically, and record the vehicle's motion and driver's maneuvers during a pre-defined time period before and after the accident. The items of the Black Box included the acceleration, yaw-rate, vehicle speed, engine RPM, braking application, steering and several digital inputs for recording driver's maneuvers. To detect the accident-related-crash, it is important to understand characteristics of the crash signal, which are much different from those of normal driving. Therefore, analytical considerations should be taken in designing pre-filtering circuits and selecting appropriate parameters for identifying crash accidents. And, it is necessary to select proper combination of motion sensors and design proper pre-filtering circuits in order to describe the vehicle's motion. The analysis algorithms were developed and implemented which can perform accurate detection of crash accidents, simulating pre-crash trajectories, and calculating parameters for reconstruction analysis of crash accidents. The developed Black Box was installed on passenger cars and several types of validation tests were conducted. Through the tests, the accuracy of the recorded data and usefulness of the analysis tool for reconstruction have been validated.

A Study on the Performance of Mechanical Crash Sensors (기계식 충돌 센서의 성능 해석)

  • Kim, K.H.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.3 no.1
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    • pp.136-142
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    • 1995
  • An analysis model is proposed for the performance prediction of typical ball and tube type mechanical crash sensors based upon mass-spring-viscous gas damping idealization. Also a construction of mechanical crash pulse generator is suggested as an experimental tool for calibration and verification of model predictions. A sensor tuning procedure for a particular set of crash pulses is suggested based upon the analysis model and the experimental tools.

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Determination of Crash Pulse to Minimize Injuries of Occupants and Optimization of Crash Components Using Response Surface Method (승객 상해를 최소화하는 충돌특성곡선의 결정 및 반응표면법을 이용한 충돌 부품의 최적설계)

  • 홍을표;신문균;박경진
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.2
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    • pp.116-129
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    • 2001
  • Traditional occupant analysis has been performed with a pre-determined crash puse which is produced from a test and the involved components are designed based on the analysis resuls. The method has limitations in that the design does not have much freedom. Howrver, if a good crash pulse is proposed, the body structure can be modified to generate the crash pulse. Therefore, it is assumed that the crash pulse can be changed to imptove the occupant crash performance. A preferable crash pulse is determined to minimize the occupant injuty. A constraint is established to keep the phenomena of physics valid. The response surface method(RSM) is adopted for the optimization process. An RSM in a commercial code is utilzed by interfacing with an in-house occupant analysis program called SAFE(Safety Analysis For occupant crash Enviroment). Design of involved components called is carried out through optimization with the RSM. The advantages of the RSM are investigated as opposed to other methods, and the tesults are compared. Also, the design under the new crach pulse is compared with that trom the pre-detetmined pulse.

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The Effect of Management Disclosure and Analysis on the Stock Crash Risk: Evidence from Korea

  • Lee, A-Young;Chae, Soo-Joon
    • The Journal of Asian Finance, Economics, and Business
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    • v.5 no.4
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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.

Development of a Finite Element Model for Frontal Crash Analysis of a Large-Sized Truck (대형트럭의 정면 충돌 특성해석을 위한 유한요소모델의 개발)

  • Kim, Hak-Duck;Song, Ju-Hyun;Oh, Chae-Youn
    • Proceedings of the KSME Conference
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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.

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Scale Modeling Technique for the Crash Analysis of Railway Vehicle Structure (철도차량 충돌 해석을 위한 축소모델링 기법 연구)

  • 김범진;허승진
    • Journal of the Korean Society for Railway
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    • v.5 no.4
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    • pp.231-236
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    • 2002
  • Todays, crash safety requirements of the railway vehicle structures become important design criterion according to the increased driving speed and the lightweight construction. Although the crash analysis using computer simulation can be effectively applied to predict the crash performance of the railway vehicles in the early design stage, the optimized design w.r.t the crash safety could be realized by the crash tests with actual prototype vehicles. However, it is very expensive and time-consuming task to perform the crash test of the railway vehicles. As a measure to cope with the problem, in this paper, the scale modeling technique is suggested and experimentally verified to predict the impact energy absorption characteristics of full scale model of aluminum extrusions sub-structures and the high-speed railway vehicle structure.

A Simplified Method to Consider Forming Effects in a Car Crash Analysis (차량충돌해석 적용을 위한 간단화한 성형이력 고려 방법)

  • Huh, J.;Yoon, J.H.;Lim, J.H.;Park, S.H.;Huh, H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • pp.259-262
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    • 2008
  • This paper introduces a simplified method to consider forming effects in a car crash analysis. Representative value was used to consider forming effects simply. Four representative values, which are the mean value of thicknesses and effective plastic strains at nodes, the median of thicknesses and effective plastic strains at nodes, were evaluated. A crash analysis of a front side member shows that analysis results from the suggested methods are similar to those from the conventional method to consider forming effects. Use of the mean effective plastic strain shows the best results. A car crash analysis for a ULSAB/AVC model under the condition of US SINCAP were carried out to demonstrate the validity of the suggested method. Analysis results show that the error of suggested method is less than 1.5%.

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