• Journal of the Korean Society for Precision Engineering
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• v.33 no.10
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• pp.781-787
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• 2016

We introduce FEST (Flight Environment Simulation Test) procedures for precise guided missiles to reliably improve systems. Flight vibration specification was established based on power spectral density curves calculated from flight test data of a high speed precise guided missile. A FEST pre-profile was developed according to flight vibration specification and delivered to a precise guided missile assembly. Vibration responses were measured by installing accelerometers on electronic components vulnerable to dynamic forces. The FEST profile was adjusted by comparing the vibration responses and the flight vibration specification. Subsequently, the FEST profile was repeatedly modified through trial and error, because the responses were similar to the flight environment. The modified FEST profile enabled performance testing of assembled precise guided missiles under simulated flight conditions on the ground, where unexpected errors could be corrected before the flight tests, leading to cost and risk reduction in the development of the precise guided missile system.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.6
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• pp.723-730
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• 2018

A well-designed flight vibration specification enables the optimum weight design of the Surface-to-Air or Air-to-Air Missile, improves the maneuverability of the flight vehicle, improves the engagement of target, and increases the price competitiveness of the components and the missile system. Conventional flight vibration specifications are used by using a somewhat higher standard as suggested in MIL-STD-810C, or based on accumulated data from developed similar missile systems. In this study, we confirmed the validity of FEA response analysis by comparing response data obtained by FEA and response data of real product. Also we proposed that each specification that reflects the structural characteristics of the place where the components are mounted is required instead of verifying all the components by a single flight vibration specification.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.6
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• pp.596-605
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• 2022

In this study, analysis of dynamic characteristics and flight vibration was performed to unmanned aerial vehicles. The analysis model was supplemented by performing a dynamic characteristic test and a random vibration test using manufactured dummy aerial vehicle. For the dynamic characteristic test, a bungee cable was used to implement the free end boundary condition. Prior to the flight vibration test using a multiple electric shaker, a random vibration test was performed to predict the excitation force during the actual flight vibration test. It was judged that the actual test could be predicted more accurately by supplementing the analysis model from the test results. In addition, it was possible to determine the feasibility of the test by predicting the excitation force of the flight vibration test.

• Journal of the Korea Institute of Military Science and Technology
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• v.26 no.3
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• pp.252-261
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• 2023

Analysis of dynamic characteristics and flight vibration test for unmanned aerial vehicles was studied by using dummy test body. The FEM model for dummy test body was supplemented by results of modal and random vibration test. The free end boundary condition to simulate flight environments was made by test setup using bungee cable. Prior to the flight vibration test using a dual electric vibration exciters, the test procedure to calculate quantitative vibration level was studied by using military specification. The actual test was successfully done by using the analysis and pretest results. From the analysis results, it was possible to determine the feasibility of the test by predicting the excitation force of the flight vibration test and to get the response of any point which could not be measured by the test. The results of this study will much contribute to the Test and Evaluation of unmanned aerial vehicles.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.4
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• pp.551-564
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• 2016

High-speed flight vehicles (HSFVs) such as space launch vehicles and missiles undergo severe dynamic loads which are generated during the launch and in in-flight environments. A typical vehicle is composed of thin plate skin structures with high-performance electronic units sensitive to such vibratory loads. Such lightweight structures are then exposed to external dynamic loads which consist of random vibration, shock, and acoustic loads created under the operating environment. Three types of dynamic loads (acoustic loads, rocket motor self-induced excitation loads and aerodynamic fluctuating pressure loads) are considered as major components in this study. The estimation results are compared to the design specification (MIL-STD-810) to check the appropriateness. The objective of this paper is to study an estimation methodology which helps to establish design specification for the dynamic loads acting on both vehicle and electronic units at arbitrary locations inside the vehicle.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.363-366
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• 2006

In general, pyrotechnic shock or pyroshock is generated during the operation of separation devices, which use explosives, such as pyrobolt, puronut, purocutter, linear shape charge, and so on. During the flight of launch vehicle, pyroshock is mainly produced at the events of satellite separation, fairing separation and stage separation. In this paper, characteristics of pyroshock are introduced in the first place and measured shock result data at the UMR of satellite mock-up during the separation tests of satellite and fairing are suggested. These results are compared with the suggested pyroshock test specification of satellite, and it finally confirms that the specification is reasonable for the qualification of satellite against pyroshock.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.713-716
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• 2010

Slosh and vibration effects of fuel inside of fuel tank can be occurred due to the acceleration and flight speed during the rotorcraft flight. It can lead to the failure of internal fuel component and fuel tank skin can be damaged. This is directly related to human survival. Military specification (MIL-DTL-27422D) specifies that stability of aircraft fuel tank and internal component against slosh &vibration load shall be verified through the qualification test procedures. This report shows the establishment of slosh and vibration test facility and KUH fuel tank qualification test result.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.6
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• pp.553-558
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• 2011

This paper describes the development and test result of S-band Transmitter flight model(FM) of STSAT-3 by satellite research center(SaTReC), KAIST. The communication sub-system of STSAT-3 is consist of two different frequency band channels, S-band for Telemetry & Command and X-band for mission data. S-band Transmitter(STX) functionally made of modulator, frequency synthesizer, power amp and DC/DC converter. The transmission data is modulated by FSK(Frequency Shift Keying) and the interface between spacecraft sub-module and STX is RS-422 standard method. The FM STX is based on modular design. The RF output power of STX is 1.5W(31.7dBm) and BER of STX is under $1{\times}10^{-5}$ which meets the specification respectively. The FM STX is delivered Spacecraft Assembly, Integration and Test(AIT) level through the completion of functional Test and environmental(vibration, thermal vacuum) Test successfully.