強度の異なる材の接合面近傍に存在するき裂のまわりの応力・歪挙動

抄録

Considerations have been conducted fundamentally on stresses·strains controlling parameter of cracked plate joined with two dissimilar materials, especially of which yield strengths are different each other, that is σ^I_Y, σ^I_Y. Attention mainly is paid to the joined plate with a crack of which tip, exists in the vicinity of joining surface of dissimilar materials. FEM analyses are applied for calculation of deformation behaviours under tension of two kinds of cracked plates: L-type specimen in which crack is perpendicular to the joining surface and P-type specimen in which crack is parallel to the ioinine surface.
Mechanical heterogeneity remarkably influences on stresses.strains in the vicinity of the crack tip when plastic deformation spreads beyond the joining surface. On the analogy of linear elastic fracture mechanics theory, the parameter, F, which controls stresses. strains in the vicinity of the crack tip has been proposed. By using two parameters; strength ratio of two materials, Sr(=σ^II_Y/σ^I_Y, and F[=σ_G/σ^I_Y)·√c/d], characteristics of stress.strain distributions of two kinds of cracked plates can be classified.