• Title/Summary/Keyword: Effects on shock response behaviors

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Wet Drop Impact Response Analysis of CCS in Membrane Type LNG Carriers -II : Consideration of Effects on Impact Response Behaviors- (멤브레인형 LNG선 화물창 단열시스템의 수면낙하 내충격 응답해석 -II : 내충격 응답거동에 미치는 영향 고찰-)

  • Lee, Sang-Gab;Hwang, Jeong-Oh;Kim, Wha-Soo
    • Journal of the Society of Naval Architects of Korea
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    • v.45 no.6
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    • pp.735-749
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    • 2008
  • For the development of the original technique of structural safety assessment of Cargo Containment System(CCS) in membrane type LNG carriers, it is necessary to understand the characteristics of dynamic response behavior of CCS structure under sloshing impact pressure. In the previous study, the wet drop impact response analyses of CCS structure in membrane Mark III type LNG carriers were carried out by using Fluid-Structure Interaction(FSI) analysis technique of LS-DYNA code, and were also validated through a series of wet drop experiments for the enhancement of more accurate shock response analysis technique. In this study, the characteristics of structural shock response behaviors of CCS structure were sufficiently figured out by careful examinations of the effects of specimen weight, drop height, incident angle, corrugation and stiffness of inner hull on its shock response behaviors. The shock response analysis of upward shooting fluid to inner hull was performed, and the reason of faster strain response than shock pressure one was also figured out.

Effects of Panax Ginseng on the Central Nervous System -Effect of Panax Ginseng on the Emotional Response in Rats- (인삼의 중추신경계에 대한 작용 -인삼이 흰쥐의 정서반응에 미치는 영향-)

  • Kim, Eung-Chan;Cho, Hang-Young;Kim, Joo-Myung
    • Korean Journal of Pharmacognosy
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    • v.2 no.1
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    • pp.23-28
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    • 1971
  • This study was planned to see whether the Panax Ginseng root has any influence upon the emotionality in rats exposed to a novel open-field and induced by a grid shock. Sixty four male albino rats whose body weight ranged from 130 to 180 gm were used. They were divided into four groups, i.e., placebo control group, 5mg/kg Ginseng ext. group, 10mg/kg Ginseng ext. group, and 20mg/kg Ginseng ext. group. Sixteen rats were subjected in each group. Open-field activity was measured in a $2.20m\;{\times}\;2.20m$ open-field that was divided into 15cm squares. Four novel objects and food pellets were put with an equal distance in the open-field. Locomotion was recorded by entering the number of squares traversed for 4 min. and behaviors which were shown at the 10-sec. period were checked by a modified Jarrad and Bunnel's observation procedure. Sensitivity to the grid shock was measured in a compartment of shuttle box. 10, 20, 30, 40, 50, 60 and 70 volt ac. 2 sec., electric shock were delivered in each subject by the grid to animal's feet. Flinch, vocalization and jumping responses were rated in each shock level. The results obtained were as follows: 1.) 5mg/kg and 10mg/kg Ginseng ext. groups were tended to increase the ambulation and exploration compared with placebo control. 2.) All Ginseng extract groups were defecated significantly less often than placebo control in the open-field and shock situation. 3.) Thresholds to the electric shock were tended to elevate in all Ginseng groups. 4.) These results suggest that Ginseng extract has a stimulant action in open-field and a tranqulizing action in feared situation.

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Explosion Resistance Performance of Corrugated Blast Walls for Offshore Structures made of High Energy Absorbing Materials (고에너지흡수 신소재 적용 해양플랜트 파형 방폭벽의 폭발 저항 성능)

  • Noh, Myung-Hyun;Park, Kyu-Sik;Lee, Jae-Yik
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.6 no.1
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    • pp.38-44
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    • 2015
  • In this paper, a finite element dynamic simulation study was performed to gain an insight about the blast wall test details for the offshore structures. The simulation was verified using qualitative and quantitative comparisons for different materials. Based on in-depth examination of blast simulation recordings, dynamic behaviors occurred in the blast wall against the explosion are determined. Subsequent simulation results present that the blast wall made of high energy absorbing high manganese steel performs much better in the shock absorption. In this paper, the existing finite element shock analysis using the LS-DYNA program is further extended to study the blast wave response of the corrugated blast wall made of the high manganese steel considering strain rate effects. The numerical results for various parameters are verified by comparing different material models with dynamic effects occurred in the blast wall from the explosive simulation.

Dynamic Characteristics Stiffened Blast-wall Structures Subjected to Blast Loading Considering High Strain-rate Effects (고속 변형률속도 효과를 고려한 폭발하중을 받는 보강형 방폭벽 구조의 동적 특성)

  • Kim, Gyu Dong;Noh, Myung Hyun;Lee, Jae Yik;Lee, Sang Youl
    • Journal of Korean Society of Steel Construction
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    • v.28 no.2
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    • pp.65-74
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    • 2016
  • A finite element dynamic simulation is performed to gain an insight about the stiffened blast wall structures subjected to blast loading. The simulation was verified using qualitative and quantitative comparisons for different materials. Based on in-depth examination of blast simulation recordings, dynamic behaviors occurred in the blast wall against the explosion are determined. Subsequent simulation results present that the blast wall made of the high performance steel performs much better in the shock absorption. In this paper, the existing finite element shock analysis using the LS-DYNA program is further extended to study the dynamic response of the stiffened blast wall made of the high-performance steel considering high strain-rate effects. The numerical results for various parameters were verified by comparing different material models with dynamic effects occurred in the stiffened blast wall from the explosive simulation.