• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.25 no.1
• /
• pp.51-56
• /
• 2012

Crashworthy fuel cells have been widely implemented to rotorcraft and rendered a great contribution for improving the survivability of crews and passengers. Since the embryonic stage of military rotorcraft history began, the US army has developed and practised a detailed military specification documenting the unique crashworthiness requirements for rotorcraft fuel cells to prevent most fatality due to post-crash fire. Foreign manufacturers have followed their long term experience to develop their fuel cells, and have reflected the results of crash impact tests on the trial-and-error based design and manufacturing procedures. Since the crash impact test itself takes a long-term preparation efforts together with costly fuel cell specimens, a series of numerical simulations of the crash impact test with digital mock-ups is necessary even at the early design stage to minimize the possibility of trial-and-error with full-scale fuel cells. In the present study a number of numerical simulations on fuel cell crash impact tests are performed with a crash simulation software, Autodyn. The resulting equivalent stresses are further analysed to evaluate a number of appropriate design parameters and the artificial neural network and simulated annealing method are simultaneously implemented to optimize the crashworthy performance of fuel cells.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.12
• /
• pp.918-923
• /
• 2018

The main function of a fuel tank is to store fuel. On the other hand, the structural soundness of the fuel tank is related directly to the survival of the crew in an emergency situation, such as an aircraft crash, and the relevant performance is demonstrated by a crash impact test. Because crash impact tests have a high risk of failure due to the high impact loads, various efforts have been made to minimize the possibility of trial and error in the actual test at the beginning of the design. Numerical analysis performed before the actual test is a part of such efforts. For the results of numerical analysis to be reflected in the design, however, the reliability of numerical analysis needs to be ensured. In this study, the results of numerical analysis and actual test data were compared to ensure the reliability of numerical analysis for the crash impact test of a rotorcraft fuel tank. For the numerical analysis of a crash impact test, LS-DYNA, crash analysis software, was used and the ALE (arbitrary Lagrangian Eulerian) technique was applied as the analysis method. To obtain actual test data, strain gages were installed on the metal fittings of the fuel tank and linked to the data acquisition equipment. The strain and stress of the fuel tank fitting were calculated by numerical analysis. The reliability of the numerical analysis was enhanced by assessing the error between the strain measurement of the upper fitting obtained from an actual fuel tank and the strain calculated from numerical analysis.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.3
• /
• pp.1054-1060
• /
• 2013

Fuel tank of a rotorcraft has a great influence on the survivability of crews. For a long time, US army has tried to develop the proper material for fuel cell of a military rotorcraft. As a result, the design specification of fuel cell, MIL-T-27422A, was issued for the first time on 1961. Through a few revisions, it has been developed to ML-DTL-27422D in 2007. It should be assured that fuel cell satisfies the requirement defined in MIL-DTL-27422D. The qualification test of this specification is classified into Phase I test for material and Phase II for fuel cell itself. This paper studies test conditions and procedures of slosh & vibration, gunfire resistance and crash impact test. They are considered as the most important tests which have a high possibility of failure. The rational consideration of this paper can improve the ability for estimating not only the validity of test procedure and test condition but test result. Based on the rational consideration, it is expected that the ability of the systematic development can be improved.

• The Korean Journal of Air & Space Law and Policy
• /
• v.33 no.2
• /
• pp.315-343
• /
• 2018

In the event of an air accident, the media and members of the general public pay attention to the victim of the accident and are deeply concerned about their actions and rewards. However, through the accident of Air China(CCA) Flight 129, which occurred in 2002, we were able to confirm that it is a real problem that the victims of the air accident as well as the victims suffer much suffering and serious aftermath. Nevertheless, Korea's system for assistance the families of victims of air accident is very poor. On the other hand, when Trans-World Airlines(TWA) Flight 800 exploded and crashed over the Atlantic Ocean in 1996, the United States enacted a law to assistance the families of the victims of the accident. According to this law, systematic assistance and management of not only the victims of the accident but also their families, minimize the additional damage of victims and victims' families and help them to get rid of the accident after the accident. In particular, the measures taken by the US authorities in response to an accident in which an Asiana Airlines flight(AAR) 214 crashed during a landing at San Francisco International Airport in 2013, made a lot of suggestions for us to assistance the victims and their families in an air accident. The purpose of this paper is to suggest the necessity of improving the system for victims and victim's family assistance in air accident. In this paper, we analyze the domestic and foreign legal systems and related cases in past accidents, identify the deficiencies of the Korean system, and derive the necessity to improve the related system. It is also important to make sure that victims' families are relieved from early psychological and economic shocks and that the results of accident investigations are reliable. Relevant ministries, airlines, and related agencies should recognize that prompt and systematic assistance and cooperation is needed to ensure that victims and families are relieved of the impact and confidence in the investigation, as is the case in the United States. In addition, efforts should be made to supplement the related laws for the assistance of aircraft victims and victims' families, to establish manuals for implementation, to plan and to implement them promptly in the event of an accident. To achieve this, it is necessary to establish regulations for the legal institutionalization of the roles and responsibilities of national and state agencies on victims of aviation accidents and family assistance. And the victim and family assistance plan that the airline has to submit to it, as specified in the current law, need to specify that item. In addition, new and supplemented contents should be integrated into a single clause or proposed as a separate special law for the purpose of applying a clear law.