• Proceedings of the Materials Research Society of Korea Conference
• /
• 1992.05b
• /
• pp.34-34
• /
• 1992

• 대한치과보철학회:학술대회논문집
• /
• 1993.12a
• /
• pp.47-48
• /
• 1993

• Proceedings of the KSEE Conference
• /
• 2008.04a
• /
• pp.33-41
• /
• 2008

• Proceedings of the KSEEG Conference
• /
• 2000.04b
• /
• pp.221-222
• /
• 2000

• Proceedings of the KWS Conference
• /
• 1993.10a
• /
• pp.141-143
• /
• 1993

• Proceedings of the KWS Conference
• /
• 1993.10a
• /
• pp.147-151
• /
• 1993

• Magazine of the Korea Concrete Institute
• /
• v.9 no.5
• /
• pp.189-196
• /
• 1997

본 연구에서는 유한요소법을 이용한 콘크리트 인장균열의 발생 및 전파양상을 모형화하기 위하여 분산균열(smeared crack) 모델의 일종인 2차원 균질화된 균열(homogenized crack)모형을 제안하였다. 제안한 모형은 인장균열면을 따라 속도 불연속계(velocity discontinuity)를 도입하고 평형방정식 빛 적합방정식을 이용하여 인장균열을 포함한 콘크리트의 구성방정식을 유도할 수 있으며 인장균열이 소성연화거동을 하는 경우. 유한요소망내에서 객관성이 유지될 수 있음을 밝히기 위하여 1차원 영역내에서 엄밀해를 유도하였다. 제안한 모형을 이용한 1차원 또는 2차원 유한요소 해석은 기존의 노치를 포함한 콘크리트 시편에 대한 실험과 상응하는 결과를 보였을 뿐만 아니라 유한요소망의 객관성이 유지되고 있음을 밝혔다. 제안한 모형은 큰 어려움없이 3차원 영역으로 확대할 수 있을 것이며 이에 대한 추가적인 연구가 계속될 것이다.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.19 no.4
• /
• pp.908-917
• /
• 1995

The constant .DELTA.K fatigue tests are performed in SS41 and its weldments to investigate crack opening behavior and fatigue crack propagation behavior at each parts of weldment and its boundary layer. The weldments were annealed after welding for the purpose of relieving residual stress. Every weldments has notch at weld metal zone, and fatigue crack propagates from weld metal zone to vase metal zone perpendicular to weld line. The Laser ISDG method is used in order to determine the crack opening ratio, this method is more precise than indirect measurement method, and faster and easier than other direct measurement method.

• Journal of the Microelectronics and Packaging Society
• /
• v.8 no.3
• /
• pp.25-30
• /
• 2001

The stress intensity factors for edge cracks located at the bonding interface between the semiconductor chip and the adhesive layer subjected to a uniform transverse tensile strain are investigated. Such cracks might be generated due to a stress singularity in the vicinity of the free surface. The boundary element method (BEM) is employed to investigate the behavior of interface stresses. The amplitude of complex stress intensity factor depends on the crack length, but it has a constant value at large crack lengths. The rapid propagation of interface crack is expected if the transverse tensile strain reaches a critical value.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.10 no.5
• /
• pp.121-129
• /
• 2006

This study look into the mechanisms of growth and magnification of the cracks and delamination in the pre-cracked RC beams repaired with carbon fiber sheets. The experimental parameters were loading type, loading speed and crack. In the experiments, it was confirmed that a failure of beams began with development and propagation of the stepped delamination in the below the loading point due to the rapid change of shear force, but mechanisms of the failure were not influenced with loading type, loading speed and pre-cracks. Particularly, in the case of beams having the pre-cracks, growth of crack concentrated at the special crack below the loading point and led to failure of the beam by delamination due to magnification of crack.