• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.5
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• pp.1562-1572
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• 1996

The rigid-plastic finite element formulation including the inertia force is derived and then the rigid-plastic finite elemnt program considering the inertia effect is developed. In order to consider the strain hardening, strain rate hardening and thermal softening effects which are frequentrly observed in high-velocity deformation phenomena, the Johnson-Cook constitutive odel is applied. The developed program is used to simulate two high-velocity deformation problemss ; rod impact test and hdigh-velocity compression precess. As a result of rod impact test simulation, it is found that the siulated result has a good agreement with the experimental observation. Through the high-velocity compression process simulation. it is also found that the accuracy of the simulated results is dependent upon the time increment size and mesh size.

• Journal of the Korea Society for Simulation
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• v.23 no.3
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• pp.33-40
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• 2014

Drifter is equipment which is hard to localize. Performance of prototype hasn't performed well compared to product of leading companies even though advanced foreign firm's product were dead copied. This study shows cases of approaching the factor which produces performance gap through drifter hydraulic analysis model which is core component of rock drill. Progression of procedure is following. 1) Securing reliability of the analysis model by comparing impact test result with analysis result. 2) Drawing a graph which indicates performance gap between prototype and drifter of advanced foreign firm by using analysis model. 3) Approaching the factor which produces performance gap with analysing variable of the analysis model. Software used for this analysis is SimulationX.

• Transactions of the KSME C: Technology and Education
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• v.5 no.2
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• pp.81-87
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• 2017

315Fr compressor motor exceeds vibration specifications. To find the reason, first a modal impact test with free-free condition is done. Second a modal test with fixed condition is done. Thereafter the test results are compared with FEM simulation results. Using free-free condition modal impact test, FEM simulation conditions (boundary, mesh..) are modified. The motor has rolling motion around 120Hz. FEM simulation also shows same result. FEM simulation will be used to develop other series compressor motors. Using this, manufacturing test model and doing test will be useless.

• Composites Research
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• v.20 no.4
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• pp.42-50
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• 2007

This paper describes the results of experiments and numerical simulation studies on the low-velocity impact damage of two different sandwich composite panels for application to bodyshell and floor structure of the BIMODAL tram vehicle. Square test samples of 100mm sides were subjected to low-velocity impact loading using an instrumented testing machine at four impact energy levels. Part of this work presented is focused on the finite element analysis of low-velocity impact response onto a sandwich composite panels. It is based on the application of explicit finite element (FE) analysis codes LS-DYNA 3D to study the impact response of sandwich structures under low-velocity impact conditions. Material testing was conducted to determine the input parameters for the metallic and composite material model, and the effective equivalent damage model for the orthotropic honeycomb materials. Numerical and experimental results showed a good agreement for damage area and the depth of indentation of sandwich composite panels created by the impact loading.

• Korean Journal of Adult Nursing
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• v.26 no.1
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• pp.1-10
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• 2014

Purpose: This study was conducted to test the impact of simulation-based education program for emergency airway management on self-efficacy and clinical performance ability. Methods: A quasi-experimental non-equivalent control group pre-post test design was used. A total of 60 nurses, 30 nurses assigned to the simulation-based education group and 30 nurses to a traditional lecture group. The treatment group received a lecture, small group workshop and team simulation whereas the comparison group received lectures. Results: The participants in the simulation-based education group reported significantly higher self-efficacy of emergency airway management compared to participants in the lecture only group (t=5.985, p<.001). The simulation-based education group showed significantly higher clinical performance ability of emergency airway management compared with the lecture group (t=5.532, p<.001). Conclusion: Simulation-based education was verified to be an effective teaching method to improve the self-efficacy, clinical performance skills of nurses in the learning of emergency airway management.

• Journal of Korean Society of Transportation
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• v.29 no.2
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• pp.59-67
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• 2011

To minimize the degree of damage in the SMART highway's punctuality and safety occurred from the car-barrier collisions, the impact conditions for longitudinal barriers in SMART highway was determined to be significantly larger than the existing maximum impact conditions. Results from computer simulation runs show that the existing domestic highest-performance roadside barrier did not satisfy the suggested impact conditions. The newly developed N-class barrier designed with computer simulation model and verified by full-scale crash tests has satisfied the SMART highway impact conditions in terms of occupant safety indexes and structural adequacy.

• Journal of the Korea Society for Simulation
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• v.25 no.4
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• pp.31-42
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• 2016

This study aims to identify the core technology for the automatic impact of the auto-sensing breaker that is one of the construction machinery which do not have a notable development success case yet in Korea. The study has been carried out as follows. Firstly, an analysis model was developed after determining the interconnection of pressure receiving area, opening area and port. And then, a simulation of situation that hard rock and soft rock are mixed was carried out to verify if it is possible to switch between long impact mode and short impact mode continuously. Lastly, the dynamic behavior of automatic control valve induced by the change of impact mode was analyzed based on the analysis result to decipher the core principle of automatic impact control.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.7
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• pp.163-170
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• 2003

The back beam for a automotive bumper was roll formed to improve performance, reduce weight and save cost. For the back beams produced by conventional stamping and roll forming, the crashworthiness analyses were carried out by numerical simulation and real impact test. The characteristic properties and applicability of the roll formed back beam are discussed from the results of the analyses.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.683-684
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• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.829-830
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• 2010