This study was discussed with the friction effects due to surface roughness of the interface between the base material and a reinforcement at the downward inclined interfacial crack under shear loading. The fracture parameter are analyzed by finite element method of the ANSYS. As the friction coefficient of the surface is assumed zero and 0.3, the fracture is analyzed. This study was analyzed with inclination angles about 0 degrees, 45 degrees and 90 degrees. As the results, at the inclination angle of 0, the energy release rate is reduced by about 3%. About 16%, and 2% are decreased at 45 degree and 90 degree respectively. If the inclination angle is 45 degrees, the friction effect by the sliding resistance between the interface was found to be most effective.

In this study, the effect of downward inclined interface about interfacial crack of bimaterials are discussed. The fracture parameter are analyzed by finite element method of the ANSYS. The energy release rates, displacement jump and stress distribution were analyzed as the gradient variation of inclined interfaces. As a results, in case of positive shear displacement was applied, the energy release rates not varied with gradient of inclined interface increasing. However in case of negative shear displacement was applied, the energy release rates decreased with gradient of inclined interface increasing. Due to the inclined interface contact, the shielding effect relatively increased as the gradient of inclined interface was increased.

In this study, the crack initiation and propagation behavior of interfacial crack in bimaterial are discussed. Normal crack opening displacements(NCOD) and stresses are analyzed by finite element method using ANSYS and used for extracting fracture parameters. The energy release rates can not explained the initiation and crack propagation velocity of interfacial crack. Initial velocity of crack propagation is dependent upon the normal and shear stress behind of crack tip. The crack propagation velocity of interfacial crack is very dependent upon the normal and shear stress behind of crack tip. In case of negative shear displacements increase in interfacial crack, initiation delay of crack propagation is dependent upon the negative shear stress ahead of crack tip due to the suppressing of crack opening. In case of positive shear displacements increase in interfacial crack, initiation delay of crack propagation is dependent upon the stress behind of crack tip due to the stress decrease. The fracture toughness increase is due to the initiation delay of crack propagation.

In this study, the effect of interface friction coefficient about interfacial crack of bimaterials are discussed. The fracture parameters are analyzed by finite element method using ANSYS. With increasing the interface friction coefficient, normal crack opening displacements and normal stress distributions are analyzed. In this case with surface contact in interface crack, the energy release rates decreases with interface friction coefficient increasing. Increase in the friction coefficient of the crack surface are tend to suppressing for the initiation of interfacial crack. In this case with surface non-contact, the energy release rates are constant with interface friction coefficient increasing, and so the friction coefficient are not related with the fracture parameter.

다양한 평면변형률 시편들의 균열선단 탄소성 응력상태들에 대한 경우, 여러 연구들을 동해, J-T접근방법의 유효 타당성이 충분히 검증되어졌다. 그러나 J-T 두 변수에 의한 균열선단 응력장 예측의 타당성을 보편화시키기 위해서는, 평면변형률 시편들과 같이 이상화된 구조가 아닌 실제적인 3차원 구조형상에 대한 연구가 필요하다. 이를 배경으로 본 연구에서는 평판과 직관에 대해 완전 3차원 유한요소해석을 수행하여 얻어진 응력장과 계산된 J-T두 변수로 예측되는 응력장을 비교함으로써, J-T 접근방법의 유효성 내지 한계성을 규명하였다.