• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.05a
• /
• pp.220-223
• /
• 2007

Acoustic test of the payload fairing of Korea satellite launch vehicle was conducted to verify the performance of acoustic protection system installed inside the payload fairing. This paper briefly introduces the acoustic test procedures and its results. Overall 148 dB acoustic loads were exerted on the payload fairing structures which mated with the upper stage structure of the launch vehicle. In order to verify the increase of insertion loss by the acoustic protection system, two kinds of test were performed. One is conducted with acoustic protection system and the other without acoustic protection system. Internal acoustic loads as well as external ones were measured and the measured insertion losses were compared with the requirement. The results showed that the acoustic protection system increases the insertion loss by more than 6 dB above 125 Hz. They also indicated that some design modification of Helmholtz resonator array is required to increase the insertion loss at a cavity resonant frequency.

• Journal of Auto-vehicle Safety Association
• /
• v.3 no.2
• /
• pp.11-16
• /
• 2011

In recent years, rapid-increasing market share of compact cars and SUVs has brought for both consumer and automaker to pay more attention on crash compatibility between the compact passenger vehicles and the light trucks (i.e., Pickups and SUVs). Vehicle compatibility regarding both self and partner protection in frontal crash of different class vehicles is one of hot issues in vehicle safety. Furthermore, it is expected that the amendment of UNECE-Regulation 94 to implement compatibility issues in couple of coming years. In this study, conceptual design of compatibility compliant frontal vehicle structure which subjects to improve? the distribution of frontal crash loading and structural engagement between vehicles is introduced. The effects of proposed vehicle structure on both possible candidates (i.e. FWRB, FWDB and PDB) for a compatibility evaluation test procedure and car-to-car crash are also investigated.

• Journal of Ocean Engineering and Technology
• /
• v.32 no.3
• /
• pp.208-212
• /
• 2018

In this paper, we focus on planing avoidance control for a supercavitating underwater vehicle based on the potential function method. The planing margin can be calculated using the relative position between the cavity center and vehicle center at the end of the vehicle. The planing margin was transformed into a limit variable such as the pitch angle and yaw angle limit. To prevent the vehicle attitude from exceeding the limit variable, a potential function based planing envelope protection method was proposed. The planing envelope protection system overrides commands from the tracking controller, and the vehicle attitude converges to a desired angle, in which the potential function is minimized. Numerical simulations were performed to analyze the physical feasibility and performance of the proposed method. The results showed that the proposed methods eliminated the planing, allowing the vehicle to follow tracking commands.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.22 no.1
• /
• pp.36-45
• /
• 2014

Pedestrian to vehicle traffic accidents show a very high mortality rate compared to the frequency of occurrence. In order to improve the pedestrian protection performance of the vehicle, the korean government added a "pedestrian safety" entry from the year 2007. The performance for pedestrian protection of current vehicles gradually improved compared to the past, but it is still insufficient. It was found that the pedestrian protection performance was very weak, such as the top of the bonnet, the A-pillar and under the front windshield. A application of an active hood and pedestrian protection airbags can be countermeasures for these weak points of pedestrian safety. The active hood and pedestrian protection airbags are designed and manufactured to apply to the top of the hood and to the bottom of the windshield. The manufactured system is equipped in a test vehicle and evaluated based on the Korea New Car Assessment Program(KNCAP) test procedures for the performance of pedestrian safety. As a result, the outstanding effect of pedestrian protection has been achieved by the active hood and the pedestrian protection airbag. The rates of pedestrian injury are reduced by 82.2% and 95.4%, respectively.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.26 no.3
• /
• pp.302-312
• /
• 2023

This paper describes the analysis of lightning strike zoning, the indirect lightning data simulation and the protection design for lightning indirect effects of equipment by lightning strike for unmanned aircraft consisting of composite wings. Through the analysis of lightning strike zoning according to the external shape of unmanned aerial vehicles, the structure areas that should be protected during lightning strike is derived, and the protection requirements of lightning indirect effects for flight critical equipments and equipment that must be operated upon lightning strike was derived. Lightning protection levels according to the location of mounting equipment and surrounding structure materials for each equipment was derived, and the protection design of the unmanned aerial vehicle with composite structures was also proposed from direct effect of lightning. Later, the lightning protection technology will be verified by the ground test of lightning direct and indirect effects.

• Journal of Auto-vehicle Safety Association
• /
• v.4 no.2
• /
• pp.11-16
• /
• 2012

In 2014 Flex-PLIfor the pedestrian protection will be applied to NCAP test. The most significant feature of Flex-PLI is constructed with segmental bone cores for the femur and tibia regions. So it can be more reproducible by representing pedestrian injuries such as knee ligament and tibia injury during the pedestrian crash against vehicle. In this paper, Analyzed the characteristics of Flex-PLI through the structural analysis and the test results by using Flex-PLI for our compact vehicles. Finally countermeasures into compact vehicle were proposed to fulfill the injury criteria of Flex-PLI.

• 한국방재학회:학술대회논문집
• /
• 2008.02a
• /
• pp.517-519
• /
• 2008

2007, Pedestrian protection test is operated by Korea ministry of construction & transportation. This paper focused on small size vehicle cowl structure type for reducing pedestrian head injury.

• Journal of Auto-vehicle Safety Association
• /
• v.6 no.1
• /
• pp.16-21
• /
• 2014

Recently Korea and many countries are legislated for pedestrian protection as following the GTR(Global Technical Regulation). Most NCAP organization have been applying pedestrian protection results in their own rating system in individual or overall rating. Euro NCAP agency has been introduced it first. From the beginning, Euro NCAP had assessed occupant and pedestrian protection. It has become to strengthen a pedestrian protection protocol every time published. Korea NCAP also has been rating pedestrian protection with overall rating system. This paper proposed to study new pedestrian protection protocol especially upper leg in order to find injury response based on physical test. On Euro NCAP, the upper leg injury are assessed two kind of value which are bending moment and force.

• Interaction and multiscale mechanics
• /
• v.3 no.4
• /
• pp.405-414
• /
• 2010

The performance of full-scale steel and composite bridge safety barriers under vehicle crash is evaluated by using the nonlinear explicit finite element code LS-DYNA. Two types of vehicles used in this study are passenger car and truck, and the performance criteria considered include structural strength and deformation, occupant protection, and post-crash vehicle behavior. It can be concluded that the composite safety barrier satisfies all performance criteria of vehicle crash. Although the steel safety barrier satisfies the performance criteria of occupant protection and post-crash vehicle behavior, it fails to satisfy the performance criterion of deformation. In all performance evaluations, the composite safety barrier exhibits a superior performance in comparing with the steel safety barrier.

• Journal of Auto-vehicle Safety Association
• /
• v.13 no.4
• /
• pp.99-105
• /
• 2021

Vehicle occupant postures are anticipated to vary more widely during automated driving and to become more significant in terms of the autonomous vehicle safety. Experimental and computational approaches are needed to investigate and evaluate occupant behaviors during automated driving in general. However the validity and effect of such occupant postures are unknown, thus it is necessary to examine occupant behaviors and injury countermeasures for various occupant postures. This study was focused on the development and evaluation of restraint system model for occupant behavior examinations in the first step according to autonomous vehicle occupant safety. The finite element models of dummy and restraint system were set up and simulation results showed overall model performance and safety tolerances of different reclined occupant postures during frontal impact loading.