• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2014.10a
• /
• pp.267-272
• /
• 2014

In this paper, we analyze the characteristics for the driving shock resistance of the military vehicle through the bump test. Prior to the experiment, theoretical analysis was performed by using the SRS(shock response spectrum) and VRS(vibration response spectrum) analysis method. And we estimated the characteristics for the driving shock resistance of the military vehicle. Bump test was performed using the acceleration sensor and the driving test at a different speed. We evaluated the characteristics for the driving shock resistance of the military vehicle based on the result. And predicted values were compared with the theoretical analysis. In addition, we evaluated the results of the theoretical prediction of the SRS and the VRS analysis. And we evaluate the suitability of the prediction method at military vehicle shock analysis.

• Journal of the Society of Naval Architects of Korea
• /
• v.42 no.5 s.143
• /
• pp.493-498
• /
• 2005

Underwater explosion shock response analysis of a MIL-S-901D Standard Floating Shock Platform(SFSP) was performed using LS-DYNA/USA, and the accuracy of analysis results was examined through the comparison of them with the existing test results. Surrounding fluid as well as the SFSP was included In a three dimensional finite element model for the consideration of the cavitation effects of UNOEX shock wave. It was confirmed that the analysis results could predict accurately the shock behaviors of the SFSP, and the response characteristics according to heavy weight shock tests could be figured out well.

• Journal of KSNVE
• /
• v.11 no.3
• /
• pp.449-454
• /
• 2001

The shock performance of hard disk drives has been a serious issue for portable computers and AV application HDD. Focusing on the motion of an actuator, we investigated non-operational shock mechanism and studied several parameters that affect the shock performance by experimental analysis. It was found that there are two important factors fort the actuator to endure high shock revel. One is a shock transmissibility and the other is a beating between the arm blade and the suspension. To generalize the shock transmissibility, the concept of shock response spectrum was introduced. The shock response spectrum of the actuator system was obtained experimentally and compared with that of an analytical single degree of freedom model. It was found that there was a good agreement. The first bending natural frequency of the arm blade was found to be the most important factor for the low shock transmissibility. By applying the shock response spectrum and avoiding the beating, we could design an actuator of high shock performance.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.14 no.12
• /
• pp.1347-1353
• /
• 2004

With respect to the researches of the optical flying head(OFH) , the head-gimbal assembly should be analyzed to guarantee the stable fabrication and the characteristics of shock resistance. The suitable design is proved through the Probabilistic analysis of the design parameters and material properties of the model. Probabilistic analysis is a technique that be used to assess the effect of uncertain input parameters and assumptions on your analysis model. Using a probabilistic analysis you can find out how much the results of a finite elements analysis are affected by uncertainties in the model. Another factor is analysis of the dynamic shock analysis. For the mobile application, one of the important requirements is durability under severe environmental condition, especially, resistance to mechanical shock. An important challenge in the disk recording is to improve disk drive robustness in shock environments. If the system comes in contact with outer shock disturbance. the system gets critical damage in head-gimbal assembly or disk. This paper describes probabilistic and dynamic shock analysis of head-gimbal assembly in micro MO drives using OFH slider.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2001.11b
• /
• pp.761-765
• /
• 2001

Shock responses of the MIL-S-901D standard floating shock platform("SFSP") subject to underwater explosions(UNDEX) are analyzed by using the LS-DYNA/USA. For the analysis, surrounding fluids as well as the SFSP are included in a 3D FE model to consider the cavitation effects of the UNDEX shock wave. The calculated results are compared with the existing test results and it is confirmed that the analysis results predict accurately the shock behaviors of the SFSP.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2012.04a
• /
• pp.588-593
• /
• 2012

Nowadays, various forms of electro-optical rifle scope have been developed and used in order to enhance the accuracy of small arms. However, firing shock acceleration has characteristics of pyroshock having a big acceleration value with very short duration time, which the electro-optical scopes should be designed to sustain. In this paper, the firing shock acceleration, which is transmitted to the electro-optical scope, was measured and SRS (Shock Response Spectrum) analysis was performed by using the measured firing shock acceleration. Furthermore, a shock test condition using a drop-table shock tester, which can simulate the actual firing shock acceleration, was devised. The devised shock test condition will be utilized to test the electro-optical scope itself before attaching it to the small arms.

• Journal of the Korean Society for Precision Engineering
• /
• v.33 no.10
• /
• pp.805-811
• /
• 2016

Prior to installation in a navy ship, shipboard equipment should be qualified by shock test requirements. The multi-function console mounted on the elastic platform of the ship should also withstand given shock loads. In this study, both real shock test methods, as well as numerical computer simulations using the finite element method were used to verify structural durability under shock load conditions. First, we used domestic test facilities to perform possible shock tests, including an impact hammer test, a drop table test and a shaker shock test. Full model tests satisfying the shock response spectrum level were performed. Thereafter, an analytical model of the complex console structure was built by the finite element method. Finally, numerical results were verified by modal test results of the real product and an FEA analysis was also performed with a full model transient response analysis.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2001.05a
• /
• pp.490-495
• /
• 2001

This paper deals with an analysis and countermeasure for improving the shock performance of laptop computers. The shock analysis is carried out by using the commercial program of LS-DYNA3D. Also the analysis is verified by the measurements from modal tests and shock tests. The available countermeasures are investigated theoretically and experimentally to find the effective methods of reducing the shock acceleration on hard disk driver during one side fall test. The hard disk drive is the most sensitive part in a laptop computer. This research shows the effects of the spring constant of rubber pad, the reinforcement of mechanical parts and the location of a hard disk driver, on the shock reduction.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2000.06a
• /
• pp.1180-1184
• /
• 2000

The dynamic design analysis method (DDAM) to analyze and evaluate shock response of the equipment system mounted in ships are discussed. Theoretical background of the DDAM based on the general shock response analysis was introduced. Spectrum dip effect between the equipment system and supporting structure was specially focused being peculiar to general shock response analysis. Actual shock design values used in the DDAM were reviewed in their category, general trend and establishing process. Aspects of DDAM analysis using MSC/NASTRAN were shortened. As a conclusion DDAM is regarded as a reasonable way of analysis for the onboard equipment system due to the underwater shock.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.16 no.11 s.116
• /
• pp.1132-1139
• /
• 2006

Non-contact underwater explosions against surface ship could cause extensive equipment damage during wartime service. Thus, the need to develop methods for the design of shock resistant equipment structures and systems was strongly established. In analytical methods, DDAM(Dynamic Design and Analysis Method) and transient repsonse method are used for ship shock design. In this paper, to analyze the characteristics of DDAM, medium weight shock test, DDAM and transient response analysis for missile system equipment are performed.