• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.5
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• pp.115-126
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• 2009

This paper studied on the application of the crashworthiness regulations of Korean Railway Safety Law and Urban Transit Safety Law to the urban Maglev vehicle of KIMM. The Urban Maglev vehicle has to comply with the crashworthiness regulations for urban transit vehicles. The collision load cases have been simulated by using explicit finite element analysis. From the numerical results, the crashworthiness regulations of the Urban Transit Safety Law were completely satisfied, but maximum crash pulse requirement in 25 km/h crash event and no plastic deformation requirement in 10 km/h crash event in the Korean Railway Safety Law were not. If a commercial urban Maglev vehicle is developed in the near future, it is necessary that some soft buffing and energy absorbing devices are adopted in its front end so as to satisfy the crashworthiness regulations of the Korean Railway Safety Law.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.5
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• pp.415-422
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• 2014

There has been a lot of discussion to revise military helicopter crashworthiness design criteria. In this paper, newly revised crashworthiness criteria is analyzed centering around the Crashworthiness Index which is the core content of revised criteria. The Crashworthiness Index(CI) was conceived as an adequate method to quantify the crashworthiness capabilities of a rotorcraft design. The index can rate how well a new or derivative design complies with design requirements. The CI rating is made up of seven assessment areas. While the Basic Airframe Crashworthiness(BAC) area tends to be an objective calculation, other areas of the CI tend to be more subjective. Therefore, in this paper, detail CI calculation process for the BAC area is analyzed to inspect the effectiveness of revised criteria.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.2040-2045
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• 2008

The priority of Crashworthiness concept for rolling stock is progressively increasing to reduce the damage of drivers and passengers as well as the car. For the first step of this research, the analysis of the crash elements have been performed. Also the longitudinal collapse force and mode is important point for whole carbody structure to guarantee the lower force at end part rather than the main passenger area. The carbody quasi-static collapse analysis and real test has been performed in the research. The crash elements FEA and test has been performed as well. After the initial Analysis and test, the correlation analysis between the FEA and test has been performed by FEA tunning. All this result will be used for real crashworthiness design for carbody structure.

• Steel and Composite Structures
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• v.23 no.1
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• pp.31-40
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• 2017

This article aims at presenting multi objective optimization of parameters that affect crashworthiness characteristics of bi-tubular structures using Taguchi method with grey relational analysis. To design the experiments, the $L_9$ orthogonal array has been used and based on that, the inner tubes have been fabricated by varying the three influence factors such as reference diameter, length difference and numbers of sides of the polygon with three levels, but all the outer cylinders have the same diameter and length 90 mm and 135 mm respectively. Then, the tailor made bi-tubular steel structures were subjected into quasi static axial compression. From the test results it is found that the crushing behaviors of bi-tubular structures with different combinations were fairly significant. The important responses (crashworthiness indicators) specific energy absorption and crush force efficiency have been evaluated from load - displacement curve. Finally optimal levels of parameters were identified using grey relational analysis, and significance of parameters was determined by analysis of variance. The optimum crashworthiness parameters are reference diameter 80 mm, length difference 0 mm and number of sides of polygon is 3, i.e., triangle within the selected nine bi-tube combinations.

• Composites Research
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• v.21 no.1
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• pp.22-29
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• 2008

This paper presents the evaluation of crashworthiness and rollover characteristics of low-floor bus vehicles made of aluminum honeycomb sandwich composites with glass-fabric epoxy laminate facesheets. Crashworthiness and rollover analysis of low-floor bus was carried out using explicit finite element analysis code LS-DYNA3D with the lapse of time. Material testing was conducted to determine the input parameters for the composite laminate facesheet model, and the effective equivalent damage model for the orthotropic honeycomb core material. The crash conditions of low-floor bus were frontal accident with speed of 60km/h. Rollover analysis were conducted according to the safety rules of European standard (ECE-R66). The results showed that the survival space for driver and passengers was secured against frontal crashworthiness and rollover of low-floor bus. Also, The modified Chang-Chang failure criterion is recommended to predict the failure mode of composite structures for crashworthiness and rollover analysis.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.9
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• pp.734-739
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• 2013

Representative crashworthiness requirement documents for military helicopter are MIL-STD-1290 and the Aircraft Crash Survival Design Guide(ACSDG) which were lastly revised in the 1980's. Taking analysis results of diverse U.S. Army helicopter mishaps into account, we can say that adequate guidelines do not exist to ensure crashworthiness of new generation aircraft. In this paper, U.S. Army helicopter mishap analysis conducted by U.S. Army Research, Development and Engineering Command(RDECOM) is readjusted to review the basis of new crashworthiness design criteria for military helicopter, in other words, Full Spectrum Crashworthiness Criteria(FSCC). This analysis effort is a part of FSC development. This effort was to research and quantify the dynamics of military aircraft crashes to be used as the quantitative basis for new design criteria.

• Composites Research
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• v.24 no.5
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• pp.9-16
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• 2011

This paper describes the crashworthiness evaluation and performance improvement of tilting train made of sandwich composites. The applied sandwich composite of carbody structure was composed of aluminum honeycomb core and glass/epoxy & carbon/epoxy laminate composite facesheet. Crashworthiness analysis of tilting train was carried out using explicit finite element analysis code LS-DYNA 3D. The 3D finite element model and 1D equivalent model were applied to save the finite element modeling and calculation time for crash analysis. The crash conditions of tilting train were conducted according to four crash scenarios of the Korean railway safety law. It found that the crashworthiness analysis results were satisfied with the performance requirements except the crash scenario-2. In order to meet the crashworthiness requirements for crash scenario-2, the stiffness reinforcement for the laminate composite cover and metal frames of cabmask structure was proposed. Consequentially, it has satisfied the requirement for crash scenario-2.

• Advances in aircraft and spacecraft science
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• v.2 no.4
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• pp.391-401
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• 2015

Crashworthiness design and certification have been and will continue to be the main concern in aviation safety. The effects of roll angles on fuselage section crashworthiness for typical civil transport category aircrafts were investigated. A fuselage section with waved-plates under cargo floor is suggested, and the finite element model of fuselage section is developed to simulate drop test subjected to 7 m/s impact velocity under conditions of 0-deg, 5-deg, 10-deg and 15-deg roll angles, respectively. A comparative analysis of failure modes, acceleration responses, and energy absorption of fuselage section under various conditions are given. The results show that the change of roll angles will significantly affect fuselage deformation, seat peak overloads, and energy absorption. The crashworthiness capability of aircraft can be effectively improved by choosing appropriate landing way.

• Journal of Aerospace System Engineering
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• v.7 no.2
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• pp.35-41
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• 2013

Crashworthiness design concept in the helicopter development is still under evolutionary stage. Survivability in the event of a crash was remarkably improved and this fact can be recognized by the analysis results on the AH-64 Apache and UH-60 Black Hawk crash accidents. Those two models are the first ones in which the crashworthiness design concept was applied with a full-scale requirement. Here we need to notice that under-design of the system results in unexpected injuries and deaths while over-design of the crashworthy elements result in unnecessary weight and costs. If landing gear system would be verified to have enough energy absorption capability in the specified vertical velocity interval, then design requirements of the airframe, fuel system and seats could be modified positively. In this paper, the right and systematic crashworthiness design concept is reviewed on the assumption that design requirements of some crashworthy elements could be partially tailored.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.748-754
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• 2008

This paper studied on the application of Korean Railway Safety Law and Urban Transit Safety Law in Crashworthiness Regulations to the urban maglev vehicle of KIMM. The crashworthiness regulations for urban transit vehicle should be satisfied to the urban maglev vehicles according to crash analysis results using the explicit finite element method. However, according to its numerical results, the crashworthiness regulations of Korean Railway Safety Law were partially satisfied except the coupling and shunting condition. When a commercial urban maglev vehicle is developed in the near future, the crashworthiness regulations of Korean Railway Safety Law should be considered and satisfied during its structural design stage in some details