• 대한기계학회:학술대회논문집
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• 대한기계학회 2005년도 창립60주년 기념 추계 학술대회
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• pp.129.1-129.1
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• 2005

• 한국정밀공학회지
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• 제15권11호
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• pp.251-257
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• 1998

동적 파괴인성치 측정시스템과 동적 2차원 유한요소해석 프로그램을 개발하여 원자로압력용기에 사용하는 강(SA508 cl.3, SA516 gr.70)의 동적 파괴인성치와 동적 균열정지인성치를 평가하고 이에 대한 유용성을 확인하였으며, 이 시스템 을 이용하여 재료의 동적 파괴특성을 규명하였다. SA508 cl.3와 SA516 gr.70의 동적 균열전파속도(a)에 대응하는 동적 응력확대계수 (K(a))에 대한 실험식을 얻었으며, 동적 응력확대계수와 동적 균열전파속도와의 관계는 전형적인 "$\Gamma$" 형으로 나타남을 확인하였다.

• 한국자동차공학회논문집
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• 제6권2호
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• pp.80-91
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• 1998

In this paper, the estimation of dynamic interlaminar fracture toughness on fracture mode II in CFRP(carbon fiber reinforced plastics) laminates in made. Dynamic ENF(End Notched Flexure) apparatus used in this paper is manufactured by suing Split Hopkinson Pressure Bar. The static and impact load history in the CFRP specimen is measured by using manufactured dynamic ENF tester and 3-point bending test is carried out to find the load history. Also dynamic interlaminar fracture toughness can be found by using the J integral obrained from dynamic analysis in consideration of intertia-force effect.

• 한국해양공학회지
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• 제2권1호
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• pp.150-162
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• 1988

The dynamic fracture toughness, $K_{Id}$,is measured in the heat-treated and ion-nitrided Cr-Mo, Ni-Cr-Mo steel using standard and Precracked Charpy specimens an imstrumented impact machine. The value of $K_{Id}$and both the energy of initiate fracture, and the total energy of fracture. Since the $K_{Id}$values of the precraked impact specimens are in accord with their theoretical ones, this testing method is sufficently practical. The effect of ion-nitriding are found to be larger than the heat-treaded specimen.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1998년도 한국재료학회 춘계학술발표강연 및 논문개요집
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• pp.104-104
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• 1998

• Journal of Welding and Joining
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• 제11권1호
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• pp.42-51
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• 1993

In this study, investigations were conducted in calculating parameters of elastic-plastic fracture mechanics using single specimen. The validity of these testing methods was judged by the confirmation of multiple specimen method of stop block test. The results were as follows: In order to measure a fracture toughness using the instrumented impact test, two general requirement must be considered; One, setting up proper impact velocity considered the effect of loading and the other, the necessity of low blow test for obtaining true energy by the compliance correction. It was possible to detect a crack initiation point by calculating the compliance changing rate from a load-defection curve. Criterion of a stable crack growth, $T_{mat}$ could be estimated by using key-curve method for a base metal. and combining Kaiser's rebound compliance with Paris-Hutchison's $T_{appl}$ equation for the brittled zone of welding heat affected.at affected.d.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1994년도 춘계 학술발표 강연 및 논문 개요집
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• pp.141-141
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• 1994

• Journal of Welding and Joining
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• 제12권2호
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• pp.108-118
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• 1994

In the present study, the dynamic crack initiation toughness and total absorbed energy behavior of Heat Affected Zone(HAZ) was experimentally evaluated for SS41 steel welding. The materials were submerged arc-welded SS41 steel plate with thickness 19mm. The test temperature range was from $20^{\circ}C$(room temperature) to $-70^{\circ}C$ The HAZ of welding were divided into three sub-zones for analysis; H1, H2, H3, according to the distance from the fushion line. From the experimental studies, the reference value of dynamic crack initiation toughness $(J_{Id(R)})$ can be use to estimate dynamic fracture toughness characteristics of steel welding.

• 한국철도학회논문집
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• 제8권3호
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• pp.210-215
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• 2005

The safety evaluations of railway wheelsets make use of the static fracture toughness obtained in ingot materials. The static fracture toughness of wheelset materials has been extensively studied by experiments, but the dynamic fracture toughness with respect to wheelset materials has not been studied enough yet. It is necessary to evaluate the characteristics of the fracture mechanics depending on each location for a full-scale wheelset for high-speed trains, because the load state for each location of the wheelset while running is different the contact load between the wheel and rail, cyclic stress in the wheel plate, etc. This paper deals with the fracture toughness depend on load rates. The fracture toughness depending on load rate data shows that once the downward curve from quasi-static values was reached, subsequent values showed a slow increase with respect to the impact velocity. This means that dynamic fracture toughness should be considered in the design code of the wheelset material.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2001년도 추계학술발표대회 개요집
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• pp.247-251
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• 2001