• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.12
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• pp.1070-1079
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• 2012

The impact energy absorbing is a very important characteristic of an aircraft to enhance the survivability of occupants when an aircraft is under the survivable accident such as an emergency landing condition. The impact energy is generally transmitted into the occupant and absorbed through a landing gear, a subfloor (lower structure of fuselage), and a seat. The characteristic of crash energy absorbing of a subfloor depends on the type of an aircraft, a shape of structure, and an applied material. Therefore, the study of crashworthiness characteristics of a subfloor structure is very important work to improve the safety of an aircraft. In this study, a finite element model of a narrow body fuselage section for the 80~90 seats regional aircraft was developed and crash simulation was executed using an explicit finite element analysis. Through survey of the impact energy distribution of each structural part of a fuselage and floor-level acceleration response, the crashworthiness characteristics and performance was evaluated.

• Nuclear Engineering and Technology
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• v.43 no.5
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• pp.413-420
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• 2011

In Korea, although the concept of dry storage system for PWR spent fuels first emerged in the early 1990s, wet storage inside nuclear reactor buildings remains the dominant storage paradigm. Furthermore, as the amount of discharged fuel from nuclear power plants increases, nuclear power plants are confronted with the problem of meeting storage capacity demand. Various measures have been taken to resolve this problem. Dry storage systems along with transportation of spent fuel either on-site or off-site are regarded as the most feasible measure. In order to develop dry storage and transportation system safety analyses, development of design techniques, full scale performance tests, and research on key material degradation should be conducted. This paper deals with two topics, structural analysis methodology to assess cumulative damage to transportation packages and the effects of an aircraft engine crash on a dual purpose cask. These newly emerging issues are selected from among the many technical issues related to the development of transportation and storage systems of spent fuels. In the design process, appropriate analytical methods, procedures, and tools are used in conjunction with a suitably selected test procedure and assumptions such as jet engine simulation for postulated design events and a beyond design basis accident.

• Nuclear Engineering and Technology
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• v.53 no.6
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• pp.1858-1868
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• 2021

Resisting an accidental impact of large commercial aircrafts is an important aspect of advanced nuclear power plant (NPP) design. Especially after the 9·11 event, some regulations were enacted, which required the design of NPPs should consider the accidental impact of large commercial aircrafts. Normal working of equipment is important for stopping reactor under an impact when an NPP is in operation. However, there is a lack of reliable analysis and research on the impact test of nuclear prototype equipment. Therefore, in order to study the response of the equipment under high acceleration impact, a centrifugal pump is selected as the research object to perform the impact test. A horizontal half-sinusoidal pulse wave was applied to the working pump. The test results show that the horizontal response of the motor and flange is greater compared to other parts, as well as the vertical response of the coupling. The stress response of the pump body support and motor support is high, hence these parts should be considered in the design of the pump. Finally, combined with the damage and stress evaluation results of the pump under different amplitudes, the ultimate impact acceleration that the pump can withstand is given.

• Journal of the Korea Safety Management & Science
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• v.10 no.3
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• pp.63-71
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• 2008

This study was conducted with respect to the causal factors revealed through the investigation of the recent airlines aircraft crash accident which occurred while aircraft was on the climb-out or on the final approach. This study also highlighted the importance of flight deviation and exceedance occurrences in consideration of Flight Operational Quality Assurance Program(FOQA). Twenty airline pilots participated in the flight experiment to perform ten(10) sets of simulated approaches and landings. As a result, Twelve(12) kinds of deviation events were discovered. In this respect, The FOQA program must be fully implemented to prevent any flight safety incident under the auspices of the Korea domestic aviation community as well.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.5A
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• pp.369-378
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• 2011

In this paper, the response analysis of RC(Reinforced Concrete), SC(Steel-Plate Concrete) containment buildings subjected to a large aircraft impact is performed using Autodyn-3D as Hydrocode. Until now, the impact load in the analysis of aircraft impacts has been applied to target structures at the local area by using the impact load-time history function of Riera. However in this paper, the results of aircraft crash are analyzed by using an aircraft model similar to Boeing 767 and verified by comparing the generated history of the aircraft crash against the rigid target with another history by using the Riera's function. To estimate the resistivity of the impact, the response and safety of SC containment buildings, this study is performed by comparing the four cases of plane concrete, reinforced concrete, bonded containment liner plate at reinforced concrete, and SC structure. Thus, the different behaviors between SC and RC structures when they are subjected to the extreme impact load could be anticipated. Consequently, the improved safety is expected by replacing RC structure with SC structure for nuclear power plants.

• Journal of Aerospace System Engineering
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• v.5 no.1
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• pp.7-12
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• 2011

The goal of fire prevention research is to eliminate fires as a cause of fatal accidents and there are two main areas of research. One is to prevent flame propagation during in-flight and it addresses fire hazards. The other is to minimize the possibility of flame penetration or fuselage burn-through and it aims toward post-crash survival include crash protection, emergency evacuation and post-evacuation survival. Civil aviation authorities world-wide are trying to identify threats and measure performance for fire prevention. The results of research are standardized and given as general directions of test methods. This paper has prepared to study and present the means of compliance to the fire prevention requirements and applicable test methods.

• Journal of Aerospace System Engineering
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• v.15 no.5
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• pp.106-112
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• 2021

In this study, we performed a design and structural analysis of a blade-shaped antenna installation on the rear fuselage of a rotary wing aircraft operated by the military. When the structure is damaged while the aircraft is in operation, it is separated from the aircraft main structure and may collide with the rotor or blades to cause the aircraft to crash. Therefore, structural safety for the modified structure must be secured. The design requirement for the newly installed modified part were established, and the load condition was constructed by applying the load that may occur in the aircraft after the modification. Structure safety for the modified structure was secured by performing structure analysis. To analysis stress and deformation of aircraft structure, we developed finite element model and verified it by using hand calculation method. We confirmed the safety of the modified structure through the final structural integrity analysis.

• Journal of Advanced Navigation Technology
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• v.24 no.3
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• pp.163-172
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• 2020

Flight data recorder (FDR) for accident investigation is required to comply with EUROCAE(ED-112) standard so that flight data can be restored when exposed to extreme conditions due to aircraft crash. Since the ED-112 standard defines the general requirements for all aircraft, it is essential to analyze detailed requirements for FDR software to apply appropriate requirements selectively according to the configuration and operation concept of a specific aircraft. In this paper, the software requirements applicable to unmanned aircraft will be analyzed and the FDR software design will be proposed. Also, a software verification method for each requirement will be presented to verify that the implemented software is designed to satisfy all requirements.

• Journal of the Korea Society for Simulation
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• v.23 no.4
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• pp.151-161
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• 2014

It is very important to evaluate proper acquisition of military aircraft against future threats in our military defense field. In previous studies, the evaluation has been determined in terms of tasking order or weapon power index. These methods compare the combat-effectiveness index and the number of aircraft. However, this study provides simulation analysis of proper quantity decision based on actual operational senarios of military aircraft using System Dynamics. The method reflects the properties of military aircraft operation concepts and considers the rate of failure of main systems on subsystems, as well as repair and crash rates caused by differentials in peacetime and wartime frame.

• Nuclear Engineering and Technology
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• v.54 no.4
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• pp.1394-1405
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• 2022

The importance of ensuring the inherent safety and security has been more emphasized in recent years to demonstrate the integrity of nuclear facilities under external human-induced events (e.g. aircraft crashes). This work suggests a simulation methodology to effectively evaluate the impact of a commercial aircraft engine onto a dry storage facility. A full-scale engine model was developed and verified by Riera force-time history analysis. A reinforced concrete (RC) structure of a dry storage facility was also developed and material behavior of concrete was incorporated using three constitutive models namely: Continuous Surface Cap, Winfrith, and Karagozian & Case for comparison. Strain-based erosion limits for concrete were suitably defined and the local responses were then compared and analyzed with empirical formulas according to variations in impact velocity. The proposed methodology reasonably predicted such local damage modes of RC structure from the engine missile, and the analysis results agreed well with the calculations of empirical formulas. This research is expected to be helpful in reviewing the dry storage facility design and in the probabilistic risk assessment considering diverse impact scenarios.