• Title/Summary/Keyword: Shock Damage Evaluation

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Development of an integrated approach for Algerian building seismic damage assessment

  • Boukri, Mehdi;Farsi, Mohammed Naboussi;Mebarki, Ahmed;Belazougui, Mohamed
    • Structural Engineering and Mechanics
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    • v.47 no.4
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    • pp.471-493
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    • 2013
  • This paper presents a framework for seismic damage evaluation for Algerian buildings adapted from HAZUS approach (Hazard-United States). Capacity and fragility curves were adapted to fit the Algerian building typologies (Reinforced Concrete structures, Confined or Non-Confined Masonry, etc). For prediction purposes, it aims to estimate the damages and potential losses that may be generated by a given earthquake in a prone area or country. Its efficiency is validated by comparing the estimated and observed damages in Boumerd$\grave{e}$s city, in the aftermath of Boumerd$\grave{e}$s earthquake (Algeria: May $21^{st}$ 2003; $M_w$ = 6.8). For this purpose, observed damages reported for almost 3,700 buildings are compared to the theoretical predictions obtained under two distinct modelling of the seismic hazard. In one hand, the site response spectrum is built according to real accelerometric records obtained during the main shock. In the other hand, the effective Algerian seismic code response spectrum (RPA 99) in use by the time of the earthquake is considered; it required the prior fitting of Boumerd$\grave{e}$s site PGA (Peak Ground Acceleration) provided by Ambraseys' attenuation relationship.

A Study on the Evaluation of Shock Vibration by a Medium Characteristics (매질특성에 따른 충격진동평가에 관한 연구)

  • Song, Jeong-Un;Hong, Woong-Ki;Kim, Seung-Kon
    • Journal of Environmental Impact Assessment
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    • v.20 no.5
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    • pp.641-649
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    • 2011
  • The ground vibration has effect on the human body and the nearby structure. However, it was very difficult to estimate the damage of structure caused by the vibration. Especially, ground vibration must be estimated on the bottom of structure because it was made up of several mediums. In this study, it was considered about the shock vibration on medium characteristics as calculating the peak particle velocity and analysing the vibration waveform. The results are as follows : Firstly, the correlation coefficient of PPV(Peak Particle Velocity) and SD(Scaled Distance) was very high at the vertical component, which was represented to 0.991 in general ground medium and each 0.989, 0.961, 0.925 in concrete medium. And also, the vibration waveform at the vertical component was very good in all mediums. Secondly, the vibration waveform at the longitudinal component was represented to a great amplitude and phase difference in all mediums. It was considered that the vibration waveform occurred the damping when particle velocity by shock vibration was propagated through other medium. Thirdly, the vibration waveform in concrete medium was represented to variation of amplitude in the order of RC medium, NC=H medium, NC=S medium at the vertical component. It was considered that the particle velocity propagated fast when a medium have a big strength and density.

International Research Status on Spent Nuclear Fuel Structural Integrity Tests Considering Vibration and Shock Loads Under Normal Conditions of Transport (정상운반조건의 진동 및 충격하중을 고려한 사용후핵연료의 구조적 건전성 시험평가 해외연구현황)

  • Lim, JaeHoon;Cho, Sang Soon;Choi, Woo-seok
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.17 no.2
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    • pp.167-181
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    • 2019
  • Currently, the development of evaluation technology for vibration and shock load characteristics and spent nuclear fuel structural integrity under normal conditions of transport is being conducted in the Republic of Korea. This is the first such research conducted in the Republic of Korea and, thus, previous international studies need to be investigated and will be referred to in the ongoing project. Before 2000, several studies related to measurement of vibration and shock loads on spent nuclear fuel were conducted in the US. US national research institutes conducted uniaxial fuel assembly shaker tests, concrete block tests, and multi-axis fuel assembly tests between 2009 and 2016. In 2017, multi-modal transportation tests including road, sea, and rail transport were also performed by research institutes from the US, Spain and the Republic of Korea. Therefore, test preparation procedures, acceleration and strain measurement results, and finite-element and multi-body dynamics analysis were investigated. Based on the measured strain data, the preliminary conclusion was obtained that the measured strain was too small to cause damage to spent nuclear fuel rods. However, this conclusion is a preliminary conclusion that only reviews part of the results; a detailed review is being conducted in the US. The investigation of international studies on spent nuclear fuel structural integrity tests considering vibration and shock loads under normal conditions of transport in the US will be useful data for the project being conducted in the Republic of Korea.

Module Design and Performance Evaluation of Surge Arrester for Loading In Railway Rolling Stock (전철 탑재형 피뢰기의 모듈설계 및 성능평가기술)

  • Cho, H.G.;Kim, S.S.;Han, S.W.;Lee, U.Y.
    • Proceedings of the KIEE Conference
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    • 2000.07c
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    • pp.2038-2040
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    • 2000
  • The main objective of this paper is to design and test a new type of polymer ZnO surge arrester for AC power system of railroad vehicles. Metal oxide surge arrester for most electric power system applications, electric train and subway are now being used extensively to protect overvoltage due to lightning. Surge arresters with porcelain housing must not have explosive breakage of the housing to minimize damage to other equipment when subjected to internal high short circuit current. When breakdown of ZnO elements in a surge arrester occurs due to flashover, fault short current flows through the arrestor and internal pressure of the arrester rises. The pressure rise can usually be limited by fitting a pressure relief diaphragm and transferring the arc from the inside to the outside of the housing. However, there is possibility of porcelain fragmentation caused by the thermal shock, pressure rise. etc. Non-fragmenting of the housing is the most desired way to prevent damage to other equipment. The pressure change which is occurred by flashover become discharge energy. This discharge energy raises to damage arrester housing and arrester housing is dispersed as small fragment. Therefore, the pressure relief design is requested to obstruct housing dispersion. The main research works are focused on the structure design by finite element method, pressure relief of module, and studies of performance of surge arrester for electric railway vehicle.

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Design and Performance Evaluation of Surge Arrester for Loading in Railway Rolling Stock (전철 탑재용 피뢰기의 설계 및 성능평가)

  • Cho, H.G.;Han, S.W.;Lee, U.Y.;Kim, S.S.;Chang, T.B.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.05a
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    • pp.74-77
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    • 2000
  • The main objective of this paper is to design and test a new type of polymer ZnO surge arrester for AC power system of railroad vehicles. Metal oxide surge arrester for most electric power system applications, electric train and must not have explosive breakage of the housing to minimize damage to other equipment when subjected to internal high short circuit current. When breakdown of ZnO elements in a surge arrester occurs due to flashover, fault short current flows through the arrester and internal pressure of the arrester rises. The pressure rise can usually be limited by fitting a pressure relief diaphragm and transferring the arc from the inside to the outside of the housing. However, there is possibility of porcelain fragmentation caused by the thermal shock. pressure rise, etc. Non-fragmenting of the housing is the most desired way to prevent damage to other equipment. The pressure change which is occurred by flashover become discharge energy. This discharge energy raises to damage arrester housing and arrester housing is dispersed as small fragment. Therefore, the pressure relief design is requested to obstruct housing dispersion. The main research works are focused on the structure design by finite element method, pressure relief of module, and studies of performance of surge arrester for electric railway vehicle.

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Damage Evaluation of Adjacent Structures for Detonation of Hydrogen Storage Facilities (수소저장시설의 폭발에 대한 인접 구조물의 손상도 평가)

  • Jinwon Shin
    • Journal of Korean Society of Disaster and Security
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    • v.16 no.1
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    • pp.61-70
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    • 2023
  • This study presents an analytical study of investigating the effect of shock waves generated by the hydrogen detonation and damage to structures for the safety evaluation of hydrogen storage facilities against detonation. Blast scenarios were established considering the volume of the hydrogen storage facility of 10 L to 50,000 L, states of charge (SOC) of 50% and 100%, and initial pressures of 50 MPa and 100 MPa. The equivalent TNT weight for hydrgen detonation was determined considering the mechanical and chemical energies of hydrogen. A hydrogen detonation model for the converted equivalent TNT weight was made using design equations that improved the Kingery-Bulmash design chart of UFC 3-340-02. The hydrogen detonation model was validated for overpressure and impulse in comparison to the past experimental results associated with the detonation of hydrogen tank. A parametric study based on the blast scenarios was performed using the validated hydrogen detonation model, and design charts for overpressure and impulse according to the standoff distance from the center of charge was provided. Further, design charts of the three-stage structural damage and standoff distance of adjacent structures according to the level of overpressure and impact were proposed using the overpressure and impulse charts and pressure-impulse diagrams.

Comparison of Hsp90 and CYP1A Expression Patterns by Water Temperature Stress in Atlantic Salmon (Salmo salar) (대서양 연어(Salmo salar)의 수온 스트레스에 의한 Hsp90 및 CYP1A 발현 양상 비교)

  • Kang, Han Seung;Song, Jae-Hee;Kang, Hee Woong
    • Journal of Marine Life Science
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    • v.3 no.2
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    • pp.51-58
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    • 2018
  • Variations in water temperature are known to affect almost every part of fish physiology. The rise in water temperature due to climate change can physically damage fish. This study was conducted to evaluate the health status of the Atlantic salmon (Salmo salar) at high water temperature (20℃) than the optimum water temperature (15℃). Liver tissue exerts important metabolic functions in thermal adaptation. Therefore, liver tissue was used in this study. The evaluation method is to develop the biomarker gene using NGS RNAseq analysis and to examine the expression pattern using RT-qPCR analysis. The NGS RNAseq analysis revealed 1,366 differentially expressed genes, among which 880 genes were increase expressed and 486 genes were decrease expressed. The biomarker genes are such as heat shock protein 90 alpha (Hsp90α), heat shock protein 90 beta (Hsp90β) and cytochrome P450 1A (CYP1A). The selected genes are sensitive to changes in water temperature through NGS RNAseq analysis. Expression patterns of these genes through RT-qPCR were similar to those of NGS RNAseq analysis. The results of this study can be applied to other fish species and it is considered to be useful industrially.

Evaluation of Machinability by various cutting conditions in high machining using ball nose-end mills -Effects of cutting orientation and cutting environments- (볼엔드밀을 이용한 고속가공에서 가공경로와 가공환경에 따른 가공성 평가)

  • 이채문;김석원;이득우
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2002.10a
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    • pp.297-301
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    • 2002
  • High-speed machining generates concenter thermal/frictional damage at the cutting ed rapidly decreases the tool life. This paper I at determining the effect of cutter orienter the cutting environment on tool life, tool mechanism when down milling. In this paper, experiments were carried out in various tool and cutting environments, such as dry, wet compressed chilled air, tool life were measu evaluate machinability in high-speed milli difficult-to-cut material and die steel, Tool measured in horizontal upwards, horiz downwards, vertical upwards and vert downwards. In addition, tool life was measur dry, wet and compressed chilled air. For this a compressed chi1led-air system was manufact The results show that a horizontal cutter ori provided a longer tool life than a vertical orientation. With respect to the cutting envi compressed chilled air increased tool life. H the wet condition decreased tool life due thermal shock caused by excessive cooling high-speed mill ins and the compressed chilled had little effect.

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A Study on Insensitive Munition Test and Evaluation for Solid Rocket Motor (고체추진기관 둔감시험 평가 기법에 관한 연구)

  • Lee, Do-Hyung;Kim, Chang-Kee;Lee, Hwan-Gyu;Yoo, Ji-Chang
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2010.05a
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    • pp.129-132
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    • 2010
  • The objective of IM rocket motor is to minimize the probability of inadvertent initiation and severity of subsequent collateral damage, hence it is important to define personnel and equipment survivability to a rocket motor accident. The violent response probability associated with shock, impact and thermal effects be minimized. And during production, transportation/storage and stack of rocket motor, sympathetic detonation, giving severe effects of the propagation of adverse reaction on its surroundings, be reduced. Hence Reaction type also based on reaction results of the overpressure, fragment throw and heat flux.

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Penetrating Neck Trauma by Gunshot Injury: 1 Case Report (총상에 의한 경부 관통상 -치험 1례-)

  • Hong, Yoon Joo
    • The Korean Journal of Emergency Medical Services
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    • v.9 no.1
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    • pp.95-99
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    • 2005
  • Penetrating neck trauma by gunshot injury involving tracheobronchial tree is rare in Korea. Extensive tissue damage by cavitation, tissue fragmentation and shock wave transmission of high-velocity projectile along with associated organ injury renders high rate of mortality and morbidity. A 28 year old man in military service with gunshot wound in left cervical area presented initial symptoms of severe dyspnea and subcutaneous emphysema. Computed tomography of chest and cervical region as well as bronchoscopic evaluation was performed to confirm highly suspected injury to cervical trachea. Surgical exposure was established through a low collar incision; the damaged segment of 3.5 cm length including 2-4th tracheal rings was resected out and end-to-end anastomosis was performed. Bleeding from lacerated anterior jugular vein was controlled by ligation of both ends and a K2 bulllet was found upon inner border of body of first rib, medial to right carotid sheath and removed out. Cervical esophagus, carotid artery, internal jugular vein and recurrent laryngeal nerve were spared. Extubation was done on the first postoperative day and postoperative course until discharge on nineth postoperative day remained uneventful.

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