• Title/Summary/Keyword: High Fatigue Load

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용접구조형 대차 엔드빔의 균열원인 규명 (The cause examination of the crack of the end beam for welding structure type bogie)

  • 홍재성;함영삼;이동형;서정원
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2004년도 춘계학술대회 논문집
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    • pp.726-731
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    • 2004
  • Bogie is the connection device between carbody and wheel in railway vehicles. It is the core part that exert a important effect on the passenger safety and running safety. Bogie largely consists of bogie frame, suspension, brake, wheel set. Static and Dynamic load have acted on it complexly. When the bogie is designed, finite element method, static load test, fatigue test, running test should be considered. Some bogie frame of high speed railway freight car have the problem. It's end beam was cracked. The crack of the end beam have a bad effect on brake system. In that case, the cars would be in danger of derailment.

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열렬화된 폴리에틸렌 케이블의 충격전압에 의한 파괴특성에 관한 연구 I (A Study on the Impulse Voltage Breakdown Characteristics of Heat-Deteriorated Polyethylene Cables ( I ))

  • 곽영순
    • 전기의세계
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    • 제24권1호
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    • pp.63-69
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    • 1975
  • This study investigated the characteristics of fatigue breakdown caused by the impulse voltage of heat treated polyethylene cables through fault currents. This study attempted to obtain the badic data on the insulation design by the repeated load of impulse voltage wave zone (1*40.mu.s) on heat treated polyethylene cables. Besides this study also analysed the data involving their durability by means of the Weibull distribution. An analysis of the breakdown characteristics based upon the repeated load of impulse voltage has revealed that worn out deteriorative breakdown existed at a high voltage near the initial breakdown voltage, and that random breakdown was discovered at a voltage somewhat lower than the initial breakdown voltage. These phenomena were more remarkable especially in the case of the higher temperature treated cables.

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태백선을 주행하는 화차 엔드빔의 진동특성에 관한 연구 (A Study Vibration Characteristic of Railway Freight Car's End Beam for Taebaek Line)

  • 함영삼;문경호;홍재성;이동형;서정원
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2004년도 춘계학술대회논문집
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    • pp.378-383
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    • 2004
  • Bogie is the connection device between carbody and wheel. It is the core part that exert a important effect on the passenger safety and running safety. Bogie largely consist of bogie frame, suspension, brake, wheel set. Static and Dynamic load have acted on it complexly. So when the bogie is designed, finite element method, static load test, fatigue test running test should be considered. Some bogie frame of high speed railway freight car have the problem. It's end beam was cracked. The crack of the end beam have a bad effect on brake system. ROTEM co. made an improved end beam and applied one set to freight car. this report showed the vibration characteristic which was compared conventional bogie to improved bogie for running safety.

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풍력발전기용 피치/요 베어링의 시험절차 개발 (Development on Test Procedure of Pitch and Yaw Bearings for Wind Turbine)

  • 남주석;한정우
    • 한국생산제조학회지
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    • 제24권3호
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    • pp.355-362
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    • 2015
  • Test procedure for the design verification of wind turbine pitch and yaw bearings has been developed. Test items were selected to evaluate operational reliability of pitch and yaw bearings by considering loading and operational conditions, and by analyzing the design criteria of pitch and yaw bearings. The developed test items consisted of preliminary test, fatigue load test, extreme load test, low temperature environmental test and dismantling inspection after all the test were completed. Because it reflects the actual operational conditions of the pitch and yaw bearings, the developed test procedure has high reliability and can verify the basic design considerations in the international standard and guidelines.

이단응력에서 침탄질화처리재의 피로거동 및 수명 해석 (The Fatigue Behavior and Life Analysis of Carbornitrizing SCM415 Steel under Two Level Block Loading)

  • 송삼홍;이상훈;심원형
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1996년도 추계학술대회 논문집
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    • pp.903-907
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    • 1996
  • Under two level block loading, the carbornitrizing specimen can be expected to show different behavior from other uniform material because the properties of surface layer and inner material are different from each other. In this research, the modified Marco-Starkey cumulative theory, which considers load interaction effect, can predict the life of SCM415 carbornitrizing and original notched and smooth specimen, In the low-high test of carbornitrizing specimen which has long life, however, we may additionally consider the increase of life by means of the stress hardening of inner original material.

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Fe-Mn 제진금속을 적용한 교량용 교좌장치 (Application of Fe-Mn Damping Alloy for Divided Spherical Bearing in Bridge)

  • 한동운;김태훈;백진현;김정철;백승한;유문식
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2006년도 춘계학술대회논문집
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    • pp.1024-1028
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    • 2006
  • The Fe-Mn damping Alloys which combine a high damping capacity with good mechanical properties can provide attractive technical and economic solutions to problems involving fatigue, noise and vibration. This study is aimed at finding its applicability to divided spherical bearing in bridge. The results obtained are summarized as follows : 1) The specific damping capacity of the Fe-Mn damping alloy is superior to that of SM490B. 2) The divided spherical bearing manufactured Fe-Mn damping alloy passes the load test to confirm applicability of that in bridge.

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레이저용접부의 파괴에 미치는 잔류응력의 영향 (The Effect of residual stress for fracture behavior in the laser weldment)

  • 조성규;양영수
    • 한국레이저가공학회:학술대회논문집
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    • 한국레이저가공학회 2006년도 춘계학술발표대회 논문집
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    • pp.3-8
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    • 2006
  • The integrity of laser welded structures is decided with fracture strength and fatigue strength. This study presents fracture behavior considering residual stress in the laser welding. Experiments are conducted and analyses are performed to explore the influence of residual stress on fracture behavior of bead-on laser welded compact specimen. Fracture experiments are performed using ASTM 1820. The performed analyses included thermo-elasto-plastic analyses for residual stress and subsequent J-integral calculation. A modified J integral is calculated in the presence of residual stresses. The J-integral is path-independent for combination of residual stress field and stress due to mechanical loading. The results indicates that the tensile residual stress near crack front bring the low fracture load while the compressive residual stress bring the high fracture load compared to no residual stress specimen. These results quantitatively understand the influence of residual stress on fracture behavior.

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Structural Response of Reinforced Concrete Beams Strengthened with CERP Rod

  • Moon Do-Young;Sim Jong-Sung;Oh Hong-Seob
    • 콘크리트학회논문집
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    • 제17권6호
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    • pp.1085-1090
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    • 2005
  • Rod-type fiber reinforced polymer plastics(FRPs) similar to reinforcing steel bars have rarely been considered. In this study, an experiment was performed using beams strengthened with rod-type CFRPs and high-strength mortar overlay. The test results show that the strengthened beams not only had improved endurance limits but also improved load carrying capacities, stiffness values, and cracking loads as compared to a non-strengthened beam. Strengthened beams anchored with bolts throughout their entire span had more efficient structural behaviors, including composite behavior on the interface between the concrete and mortar, and load carrying capacity, than a strengthened beam anchored only on the end block.

중공 드라이브 샤프트의 설계에 관한 연구 (A study on the Design on the Tubular Drive Shaft)

  • 김우강;고준빈;김홍배
    • 한국기계가공학회지
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    • 제8권3호
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    • pp.7-12
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    • 2009
  • This study aims to find the friction welding and induction harden conditions, which are obtained by welding conditions, and the friction welding characteristics and induction harden conditions of tubular shaft were investigated with respect to low load test, high load test. Friction welding and induction harden machine have been widely used in manufacturing reflects of metal. The material of solid and tubular shaft selected that is used for parts of automobile steel. Such as steel are easy to be machined because of their proper material. As a result I obtained the data of friction welding conditions makes good and the condition of friction and get the tubular condition. The purpose of this study is to find fatigue test condition and induction harden characteristics design for tubular shaft.

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레이저용접부의 파괴에 미치는 잔류응력의 영향 (The Effect of residual stress on fracture behavior in the laser weldment)

  • 조성규;양영수;노영진
    • 한국레이저가공학회지
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    • 제11권2호
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    • pp.1-7
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    • 2008
  • The integrity of laser welded structures is decided in fracture strength and fatigue strength. This study made an effort to understand the fracture behavior considering residual stress. Experiments are conducted and analyses are performed to explore the influence of residual stress on fracture behavior of bead-on laser welded compact specimen. Fracture experiments are performed using ASTM 1820. The performed analyses included thermo-elasto-plastic analyses for residual stress and subsequent J-integral calculation. A modified J integral is calculated in the presence of residual stresses. The J-integral is path-independent for combination of residual stress field and stress due to mechanical loading. The results indicates that the tensile residual stress near crack front bring the low fracture load while the compressive residual stress bring the high fracture load compared to no residual stress specimen. These results quantitatively understand the influence of residual stress on fracture behavior.

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