• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.4
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• pp.1552-1558
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• 2011

In this paper, the automotive beam using aluminium foam is designed and the impact analysis is carried out. The analysis model is the beam of actual size with B- type section structure. At the frontal crash of low speed, ANSYS AUTODYN is used by predicting the behavior of deformation and its internal energy. By the use of 7075-T6 aluminum alloy, the weight is reduced as much as 55% than steel. The deformation at the bumper foam of aluminum is similar with that of steel and the impact energy reduction at aluminum is more than steel. The foam filled with aluminum as much as 50 % has more impact energy absorption than the completely filled aluminum foam.

• Transactions of Materials Processing
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• v.31 no.2
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• pp.57-63
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• 2022

The current study performed formability analysis of a heat exchanger separator for an electric vehicle to apply a high-strength aluminum sheet based on parametric analysis. Mechanical properties for sheet metal forming simulation were evaluated by tensile test, bulge test, and Nakajima test. Two-stage crash forming was established by considering the mass production process using conventional low-strength aluminum sheets. In this study, FEM for the two-stage forming process was conducted to optimize the corner radius and height for improving the formability. In addition, the possibility of a one-stage forming process application was confirmed through FEM. The prototype of the sample was manufactured as FEM results to validate the parametric analysis. Finally, this result can provide a one-stage forming process design method using the high-strength aluminum sheet for weight reduction of a heat exchanger separator for an electric vehicle.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.1
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• pp.32-39
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• 2011

The purpose of VDR capsule is to maintain a stored information securely and retrievably in the extreme environment like voyage incident. This study shows the modellings, the analyses and the experiments of the survivability test of penetration, high and low temperature fire. The capsule housing is used to protect capsule against penetration and the influences of its thickness are studied by the modelling and analysis of penetration using LS-DYNA. The phase change material and thermal insulation material are used to protect capsule against high and low temperature fire test. The thermal characteristics of various volume ratios of phase change material to thermal insulation material were conducted. Also the tests were conducted to confirm the structural and thermal reliability.

• International Journal of Highway Engineering
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• v.13 no.4
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• pp.9-17
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• 2011

It is possible to set up the Roadside Barrier which is suitable for Performance Evaluation Criteria by domestic standard. But a number of section of expressway roadside have old guardrail that was installed before reform the guideline. These poor performance guardrails threaten driver's life. There is lots of difficult problem to change old guardrails that are installed 2,777km in expressway of whole road side at the same time. Especially budget problem. The purpose of study is to develop performance improvement guardrails by the minimum reinforcement. In this study, guardrail improvement method(SB1, 3, 5 grade) is developed through crash simulation using LS-DYNA 3D and vehicle crash test. And it's expected not only to decrease of collision accident but to increase safe level. Of course one thing that can't be missing is to reduce a lot of budget of guardrail change.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.2
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• pp.98-112
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• 2018

Intentional aggressive driving (IAD) is a very dangerous driving behavior that threatens to attack the adjacent vehicles. Most existing studies have focused on the independent driving characteristics of attack drivers. However, the identification of interactions between the offender and the victim is necessary for the traffic safety analysis. This study established multi-agent driving simulation environments to systematically analyze vehicle interactions in terms of traffic safety. Time-to-collision (TTC) was adopted to quantify vehicle interactions in terms of traffic safety. In addition, a exponential decay function was further applied to compare the overall pattern of change in crash potentials when IAD events occurred. The outcome of this study would be useful in developing policy-making activities to enhance traffic safety by reducing dangerous driving events including intentional aggressive driving.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.402-408
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• 2021

Vehicle engineering analysis in the event of an accident caused by a car built on mechanical design has not been investigated in-depth but relies on the subjective experience knowledge of the investigator. This study analyzed the correlation between the speed, progress, steering, and braking before impact, which is consistent with the final stop position, by drawing a site situation chart using the CAD (CAD) program and repeating 250 crashes using the PC-Crash program. The following situations were investigated: lower impact velocity; greater impact speed of the vehicle, which is not affected significantly by the departure angle; higher vehicle speed, such as the effective impact velocity, after the impact; higher vehicle speed; and lower vehicle speed. (Ed note: I am unsure what you are saying here. It appears contradictory and not a complete sentence. Please check the changes.)The simulation results of this study identified the process of returning to the magnetic progression lane after recognizing the opposite porter while Mighty was carried out on the uphill left-curve section in a position that crossed the center line, and the collision of the porter's front left side, pushing the porter in the right diagonal direction and making the front stop towards approximately 11 o'clock.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.429-432
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• 2002

The existing recovery technique using the logging technique in the client/sewer database system only administers the log as a whole in a server. This contains the logging record transmission cost on the transaction that is executed in each client potentially and increases network traffic. In this paper, the logging technique for redo-only log is suggested, which removes the redundant before-image and supports the client-based logging to eliminate the transmission cost of the logging record. Also, in case of a client crash, redo recovery through a backward client analysis log is performed in a self-recovering way. In case of a server crash, the after-image of the pages which needs recovery through simultaneous backward analysis log is only transmitted and redo recovery is done through the received after-image and backward analysis log. Also, we select the comparing model to estimate the performance about the proposed recovery technique. And we analyzed the redo and recovery time about the change of the number of client and the rate of updating operation.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.4
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• pp.132-139
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• 2004

The open section members have been used as the members of vehicle such as automotives, airplanes and trains. When vehicles are crashed, these members have absorption of the energy and it is necessary for retainment of the survival space, and as the result, the prediction for the displacement of members in this case of the crash of vehicles is very important. The displacements of members in this case of the crash of automotives show combined aspect of both axial collapse and bending collapse. In the rollover accident when bending collapse happen, the collapse of each members is progressed by the plastic hinge which made from bending moment, and therefore the research for the behavior of members under bending moment after collapse is necessary to determine the internal energy which the members can absorb and the deformed shapes of the members on the step of design. In this paper, the characteristics of bending collapse at the members of the open cross-section were studied with experiment and numerical analysis. We made a comparative studied of the result of the experiment, and changed the axis according to the parallel-axis theorem.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.4
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• pp.234-241
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• 2002

In this study, the car crash analysis that simulates the crushing behavior of car forestructure during a frontal impact is carried out. The analysis model for front impact of a car consists of the lumped mass and the spring model. The characteristics value of masses and springs is obtained from the static analysis of a target car. The deceleration-time curve obtained from the simulation are compared with NCAP test data from the NHTSA. They show a good agreement with frontal crash test data. The deceleration-time curve of passenger compartment is classified into 3 stages; beginning stage, middle stage, and last stage. And the behavior of masses at each stage is explained. The effect of stiffness variation on deceleration of passenger compartment is resolved. The maximum loaded peak-time of torque box and dash is the main factor to control the passenger compartment's maximum deceleration.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.3
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• pp.29-34
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• 2007

Numerical analyses are carried out to evaluate the cumulative impact damage of an automotive front end bumper under the low speed crash events(CMVSS215) by using explicit code. Results of first impact simulation, which are deformed shape, thickness, stress tensors and strain tensors, are used as the initial conditions for a next impact simulation. Between the events, the residual vibration is damped out by using nodal damping, and then recovery after each event is evaluated by several methods, one of which is a springback analysis with implicite finite element analysis code. The coupled analysis scheme for the evaluation of cumulative impact damage is verified through the comparison with test results.