• Title/Summary/Keyword: Damage possibility

Search Result 826, Processing Time 0.028 seconds

철도차량의 바퀴에 대한 구조 해석 (Structural Analysis on the Wheel of Railway Vehicle)

  • 조재웅;한문식
    • 한국생산제조학회지
    • /
    • 제21권3호
    • /
    • pp.451-458
    • /
    • 2012
  • This study aims at the structural analysis with fatigue according to the configuration of railway vehicle wheel. Maximum equivalent stress or deformation is shown at the lower face in contact with wheel and rail. As model B has the maximum stress or deformation which becomes lower than model A, model B is shown to have more durability than model A. Among the cases of nonuniform fatigue loads, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable. In case of 'Sample history' with the average stress of 0 to $-10^{11}$ Pa and the amplitude stress of 0 to $10^{10}$ Pa, the possibility of maximum damage becomes 3%. This stress state can be shown with 6 times more than the damage possibility of 'SAE Bracket history' or 'SAE transmission'. The structural result of this study can be effectively utilized with the design of railway vehicle wheel by prevention and durability against its damage.

클러치의 구조 안전 해석 (Structural Safety Analysis of Clutch System)

  • 조재웅;한문식
    • 한국자동차공학회논문집
    • /
    • 제19권5호
    • /
    • pp.148-155
    • /
    • 2011
  • This study analyzes stress, fatigue and vibration at clutch on the rotation of wheel. Eigenfrequencies from 1'st to 6'th order about clutch assembly are shown with the vibration at more than 800Hz. Maximum equivalent stress is shown with the frequency of 800Hz in case of the harmonic vibration applied with force. Among the cases of nonuniform fatigue loads, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable. In case of 'Sample History' with the average stress of 0MPa to $-10^5$ MPa and the amplitude stress of 0MPa to $10^5$ MPa, the possibility of maximum damage becomes 3.23%. This stress state can be shown with 6 times more than the damage possibility of 'SAE bracket history' or 'SAE transmission'. The structural result of this study can be effectively utilized with the safe design of clutch.

헬기의 진동과 피로에 대한 내구성 연구 (Study on Durability by Vibration and Fatigue of the Helicopter)

  • 한문식;조재웅
    • 한국기계가공학회지
    • /
    • 제10권6호
    • /
    • pp.63-69
    • /
    • 2011
  • This study analyzes stress, fatigue and vibration on main rotor and body of helicopter. The maximum stress is shown on adjoint part between body and main rotor at the lower position of main rotor. As the maximum displacement amplitude is happened at 4000Hz, there is no resonance and the state of helicopter becomes safe at hovering without the abnormal air current and the disabled rotor. Among the cases of nonuniform fatigue loads, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable. In case of 'Sample History' with the average stress of 0MPa to $-10^5MPa$ and the amplitude stress of 0MPa to $8.539{\times}10^5MPa$, the possibility of maximum damage becomes 3%. This stress state can be shown with 5 times more than the damage possibility of 'SAE bracket history' or 'SAE transmission'. The structural result of this study by using the analysis of vibration and fatigue can be effectively utilized for safe and durable design of helicopter.

불규칙 피로 하중을 받는 자전거 프레임에 대한 연구 (Study on Bike Frame due to Nonuniform Fatigue Loads)

  • 한문식;조재웅
    • 한국자동차공학회논문집
    • /
    • 제20권3호
    • /
    • pp.133-140
    • /
    • 2012
  • In this study, 3 kinds of models about bike frame are simulated with static structural analysis, And fatigue life, damage and durability according to fatigue load are analyzed. A bike frame model with diamond type is compared with another model on the reinforced support with its type. In case of the reinforced support type, maximum equivalent stress or total deformation is shown with 10% or 20% more than the diamond type respectively. At both types of models, the trends of fatigue life and damage at both types are same. 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable among the cases of nonuniform fatigue loads. In case of 'Sample history' with the average stress of 0 to -1MPa and the amplitude stress of 0 to 1MPa, the possibility of maximum damage becomes 3%. This stress state can be shown with 6 times more than the damage possibility of 'SAE Bracket history' or 'SAE transmission'. In case of the reinforced support type, fatigue life becomes shorter and damage probability becomes larger at the right side installed with support than diamond type. The structural result of this study can be effectively utilized with the design on bike frame by investigating prevention and durability against its damage.

VCE에 의한 건물피해예측에 관한 연구 (A Study on Estimation of Structure Damage caused by VCE)

  • 임사환;이종락;허용정
    • 한국안전학회지
    • /
    • 제22권5호
    • /
    • pp.65-70
    • /
    • 2007
  • This paper is estimation of structure damage caused by VCE(Vapor Cloud Explosion) in enclosure. As we estimate the influence of damage which occur at gas facility in factory. We can utilize the elementary data of safety distance. In this study, the influence of over-pressure caused by VCE in enclosure was calculated by using the Hopkinson's scaling law and the accident damage was estimated by applying the influence on the adjacent structure into the probit model. As a result of the damage estimation conducted by using the probit model, both the damage possibility of explosion overpressure to structures of 20 meters away and to glass bursting of 80 meters away was nearly zero in open space explosion.

5083-O 알루미늄 합금의 진폭에 따른 캐비테이션 침식 특성 평가 (Evaluation of Cavitation Characteristics of 5083-O Al Alloy with Amplitude)

  • 이승준;김성종
    • Corrosion Science and Technology
    • /
    • 제11권5호
    • /
    • pp.205-212
    • /
    • 2012
  • With recent advances in engineering and technology, a damage on industrial machineries performing high-speed and high-power requirements has become a problem. There is an increasing possibility of cavitation damage, especially in pumps, propellers and high-speed vessels in a flowing liquid accordingly. There are several factors affecting cavitation damage on materials, including viscosity, pressure, temperature, amplitude applied. In this study, effects of cavity pressure in seawater on the damage for 5083-O aluminium alloy were evaluated by modulating amplitude. Trend of the damage with respect to time and amplitude was analyzed comparatively, and surface degradation of specimens was investigated by using Scanning Electron Microscope(SEM) and 3D microscope. The result reveals that the amount of the damage increased consistently with the increase in time and amplitude while the plastic deformation zone where no appreciable damage occurred was in less than 30 minutes.

풍수해 피해규모 파악을 위한 위성영상의 활용방안 연구 (A study on the estimation of damage by storm and flood using satellite imagery)

  • 손홍규;윤공현;이정빈;진경혁
    • 한국측량학회:학술대회논문집
    • /
    • 한국측량학회 2007년도 춘계학술발표회 논문집
    • /
    • pp.111-114
    • /
    • 2007
  • One of future remote sensing techniques for the estimation of damage by storm and flood is the extraction of water area, which could be the basis of measuring the damage by storm and flood and estimate restoration cost. This paper introduces an approach to damage estimation using satellite Image. The project site was Ansung area and a set of Radarsat-1 SAR image at 6.25m resolution was used for the test. Authors investigated methods of SAR image processing such as shadow-effect removal, orthorectification of SAR image and calculation of damage area by flood. Consequetly, this study showed that technique improvement of image processing and the best of result for extracting water area. Also, found the new possibility of damage estimation using satellite image.

  • PDF

밀폐공간에서의 VCE에 의한 건물피해예측에 관한 연구 (A Study on Estimation of Structure Damage caused by VCE in Enclosure)

  • 임사환;허용정;이종락
    • 한국산학기술학회:학술대회논문집
    • /
    • 한국산학기술학회 2007년도 춘계학술발표논문집
    • /
    • pp.42-45
    • /
    • 2007
  • This paper is estimation of structure damage caused by VCE(Vapor Cloud Explosion) in enclosure. As we estimate the influence of damage which occur at gas facility in factory. We can utilize it the elementary data of safety distance. In this study, the influence of explosion over-pressure caused by VCE in enclosure was calculated by using the Hopkinson's scaling law and the accident damage was estimated by applying the influence on the adjacent structure into the probit model. As a result of the damage estimation conducted by using the probit model, both the damage possibility of explosion overpressure to structures 20 meters away and that of overpressure to glass bursting 80m meters away showed nothing.

  • PDF

KTX 운행에 따른 가선설비 유리애자의 진동특성과 파손 가능성 검증 (The Verification of Breakage Possibility and Vibration Properties of Glass Insulators by the High-speed Railway Service)

  • 김영석;송길목;정진수;전용주
    • 전기학회논문지
    • /
    • 제58권3호
    • /
    • pp.566-572
    • /
    • 2009
  • This paper has studied breakage possibility of glass insulators by resonance and accelerated deterioration through the comparison of the natural vibration and on site vibration. The natural frequencies of the strut tube glass insulator was measured within a range of less than 1kHz. In the on site vibration, the largest frequency that was imposed on strut tube glass insulators was 80Hz with 1.13g of vertical vibration in the viaduct section, the largest vertical vibration (0.38g) was detected at 103Hz in the open route section. When site vibration and natural vibration of strut tube glass insulators were compared in terms of characteristics, the resonance frequency was not the same. In both the viaduct and open route sections, it seems that the impact by vertical vibration in strut tube glass insulators is large. It's very unlikely that glass insulators were damaged by fatigue accumulation of vibration since the possibility of damage by resonance was very low in consideration of the characteristics of natural vibration and site vibration of glass insulators. In addition, no damage was detected in the accelerated deterioration test.

Issues of Halal Supply Chain Management: Suggestion for Korean Traders

  • Lee, Hee-Yul;Hwang, Hyun-Ju;Kim, Dong-Hwan
    • Journal of Korea Trade
    • /
    • 제23권8호
    • /
    • pp.132-144
    • /
    • 2019
  • Purpose - The purpose of this paper is to suggest countermeasures to reduce the damage of manufacturers in halal industries and to increase the transparency of the halal market along with raising some problems of halal supply chain management (HSCM). Design/methodology/approach - To achieve to the aim of this research, halal supply chain is categorized as a green zone or a red zone according to the possibility of cross-contamination, and the study introduces 2 examples in Malaysia and Indonesia regarding cross-contamination. Findings - More than 70% of the companies producing halal-certified products are, ironically, non-Muslim suppliers under the halal certificate system and by using halal supply chain. Most Muslim countries do not exercise control over the completed halal supply chain. In most Muslim countries which do not exercise control over halal supply chain properly, there is always a possibility of cross-contamination of products during the processes of distribution. Research limitations/implications - This research has been conducted by accessing cases in halal supply chain. These cases are found in some Muslim countries, not all Muslim countries. Nevertheless, the authors found the possibility of these cross-contaminations in all Muslim countries, and it will damage the halal market. Originality/value - While existing studies have focused on protecting Muslim consumers by ensuring the integrity of halal products in halal supply chain, there is no research on how to protect halal product manufacturers as another important axis of halal SCM.