• Title/Summary/Keyword: Burst Test

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Construction of Korean Space Weather rediction Center: K-SRBL

  • Bong, Su-Chan;Kim, Yeon-Han;Cho, Kyung-Suk;Choi, Seong-Hwan;Park, Young-Deuk;Gary, Dale E.
    • Bulletin of the Korean Space Science Society
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    • 2008.10a
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    • pp.32.2-32.2
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    • 2008
  • A major solar radio burst can disturb many kinds of radio instruments, including cellular phone, GPS, and radar. Korea Astronomy and Space Science Institute (KASI) is developing Korean Solar Radio Burst Locator (KSRBL) in collaboration with New Jersey Institute of Technology. KSRBL is a single dish radio spectrograph, which records the spectra of microwave (0.5 - 18 GHz) bursts with 1 MHz spectral resolution and 1 s time cadence, and locates their positions on the solar disk within 2 arcmin. Hardware manufacturing is almost completed including 4-channel digitizer/FPGA. The system is currently installed at Owens Valley Radio Observatory (OVRO), and test of the operation is in progress. It will be installed at KASI in 2009. We report current status and test results of KSRBL.

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Design and Evaluation of Volute Casings for a Liquid Rocket Turbopump (액체로켓 터보펌프 벌류트 케이징의 구조설계 및 시험)

  • Yoon, Suk-Hwan;Jeon, Seong-Min;Kim, Jin-Han
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2010.11a
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    • pp.775-776
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    • 2010
  • Volute casings for a liquid rocket turbopump are designed and evaluated in a structural point of view. After the design step volute casings are manufactured by metal casting process, and then they are subjected to burst test for verification. In the burst test strains at several points are measured and compared with predicted values.

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Development of Corrosion Defect Assessment Method for City Gas Pipeline (도시가스배관 부식결함 평가방안 개발)

  • Kim, Cheol-Man;Kim, Woo-Sik;Han, Sang-In;Choi, Song-Chun
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.228-233
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    • 2004
  • The length of city gas pipeline is increasing with expansion of natural gas transmission rapidly. A lot of the expense was paid for repair and maintenance with increasing of pipeline length and the cost of repair and maintenance by the corrosion was the highest. It is necessary to evaluate integrity in case of thickness reduction by corrosion. There are a lot of assessment criteria for corrosion defect in foreign countries but they are not suitable for application in the country directly. In this work, we performed the burst test and the finite element analysis for city gas pipeline, KS D3507 and KS D3631 for city gas transmission, and developed the assessment method of corrosion defect, which is suitable for domestic condition.

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The Evaluation on the Durability and Safety of Fuel Cyliders for CNG Buses (CNG 버스용 연료용기의 내구안전성 평가)

  • Park, Yong-Hwan
    • Journal of the Korean Society of Safety
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    • v.19 no.1
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    • pp.6-11
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    • 2004
  • CNG buses were introduced in 2002 to reduce air pollution to the big cities. The durability and safety evaluation were performed for the NGV-2 type cylinders taken from two buses after 30 months of running. No external damage and no internal corrosion was observed on the container surfaces. Defect exceeding the allowable limit was not found in the UT test. Permanent volume expansion was about 1.2% which is much smaller than the required design limit. Cycling test showed no failure after 11,250cycles and burst pressures were still above the maximum design pressure. Both the longitudinal and circumferential failure mode were observed, where both the fracture strengths were far above the design limit. This study showed the present CNG fuel cylinders were safe enough for further usage.

Burst Test of Cast Al-Alloy Casing for Liquid Rocket Engine Turbopump (액체로켓엔진 터보펌프 알루미늄합금 주조케이싱 파열시험)

  • Yoon, Suk-Hwan;Jeon, Seong-Min;Kim, Jin-Han
    • Journal of the Korean Society of Propulsion Engineers
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    • v.16 no.5
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    • pp.81-88
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    • 2012
  • Turbopump is a key component in liquid rocket engines, and reducing weight while maintaining structural safety is one of the major concerns of turbopump designers. To reduce the weight aluminium alloy castings instead of steel casings are introduced. The casting process is especially useful for enhancement of productivity and for reduction of product costs. But, since castings are used in space vehicle engines, reliability cannot be compromised. Therefore, proper design, production process and thorough investigation should be performed to ensure structural integrity. In this study inlet casings for a fuel pump were casted with A356.0-T6 alloy and using one of them a burst test was conducted to ensure structural integrity. Structural analysis is performed for simulation, and with multiple strain gages strains are measured and compared with predictions.

Burst Test of Cast Al-Alloy Casing for Liquid Rocket Engine Turbopump (액체로켓엔진 터보펌프 알루미늄합금 주조케이싱 파열시험)

  • Yoon, Suk-Hwan;Jeon, Seong-Min;Kim, Jin-Han
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2012.05a
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    • pp.616-623
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    • 2012
  • Turbopump is a key component in liquid rocket engines, and reducing weight while maintaining structural safety is one of the major concerns of turbopump designers. To reduce the weight aluminium alloy castings instead of steel casings are introduced. The casting process is especially useful for enhancement of productivity and for reduction of product costs. But, since castings are used in space vehicle engines, reliability cannot be compromised therefore proper design, production process and thorough investigation should be performed to ensure structural integrity. In this study inlet casings for a fuel pump are casted with A356.0-T6 alloy and using one of them a burst test is conducted to ensure structural integrity. Structural analysis is performed for simulation, and with multiple strain gages strains are measured and compared with predictions.

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Geographical Variation in Bud-burst Timing of Zelkova serrata Provenances (느티나무 산지별 개엽시기의 지리적 변이)

  • Kim, In Sik;Han, Sang Urk;Lee, Wi Young;Na, Sung Joon
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.15 no.3
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    • pp.191-200
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    • 2013
  • This study was conducted to examine the geographic variation of bud phenology of Zelkova serrata provenances. Data were collected from Gangneung, Yilmsil, Hwaseong and Jinju plantations which were parts of the 6 provenance trials established by Korea Forest Research Institute in 2009. The 16 provenances were included in these trials. The starting date of bud burst and finishing date of leaf expansion were investigated from April to May every other day. The four geographic factors and fifteen climatic factors of the test sites and provenances were considered in this study. Canonical correlation analysis was conducted to examine the major factors affecting the bud phenology between test sites and provenances. The study results suggested that the major factors affecting the timing of bud burst were the differences of extremely high temperature (March-October), annual mean temperature, mean temperature (March-October), extremely high temperature (July-August) and mean humidity (June-October) between test site and provenance. The provenances with lower mean or high temperature than those of plantation showed the earlier bud burst and leaf expansion. It showed a typical north-south or low-high temperature cline. Finally, we discussed the implication of the tree breeding program of Z. serrata based on these results.

Effect of Acoustic Emission During a Fatigue Test with Defect for Type II Gas Cylinder (피로시험시 발생하는 음향방출신호를 이용한 Type II Gas Cylinder의 손상평가)

  • Jee, Hyun-Sup;Lee, Jong-O;Ju, No-Hoe;So, Cheal-Ho;Lee, Jong-Kyu
    • Journal of the Korean Institute of Gas
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    • v.16 no.2
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    • pp.18-24
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    • 2012
  • This research seeks to evaluate damage on type II gas cylinder by an acoustic emission test when executing 20000 cycles fatigue test and thereafter burst test. Used gas cylinders in the experimental are three types as follows; one is sound cylinder, others are cylinders which contain longitudinal and transverse artificial defect. The size of artificial defect is a depth of 3 mm, width of 3 mm and length of 50 mm. In the case of the cylinder which artificial defect, unlike the expectation that it will burst in low pressure, the burst pressure of the cylinder did not differ much according to whether or not there were defects. However, when there was longitudinal defect, the location of burst was near the location of defect. This leads to the effect in which the thickness of the composite material becomes thinner according to the length of the longitudinal defect and this is judged to have an effect on the location of initiation and growth of crack in the liner. Also, for the acoustic emission signal, when there is longitudinal defect, the ratio of an event occurring at defect position among overall hits is more than 50 %, and the source location also accords very precisely with defect position.

Process Design and Experimental Verification of Airbag Inflator Cap Forming (에어백 인플레이터 캡 성형 공정 개발 및 검증)

  • Lee, D.K.;Lee, M.S.;Park, J.W.;Kang, B.S.
    • Transactions of Materials Processing
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    • v.27 no.4
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    • pp.201-210
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    • 2018
  • An airbag is an essential automotive component used in all kinds of vehicles such as an internal combustion engine and an electric motor vehicle and is used to minimize the damage of an occupant in the event of an accident. Airbag-related parts are being monopolized by a small number of foreign companies around the world. In this situation, it is necessary to develop and research the airbag-related part molding technology for expansion of the domestic airbag-related market and corporate export. As a part of this research, we have developed a mold for airbag inflator cap. The development consists of three steps which are the design of components, analysis of the design and verification of it. In the case of the design, the transfer type mold was designed for the multi-cylindrical shaped feature. Analysis was then conducted on the design. By examining the results of analysis, changing features and numbers of punches and dies were added in the analysis and repeatedly analyzed. After the addition, proper dimensions from the analysis were achieved, and prototypes were practically produced and verified. In the case of prototype verification, Pressurizing Burst Test was conducted on the existing products and the prototype. By comparing the results of the test, the possibility of replacing the existing product of the airbag inflator cap is presented in this paper.