@article{oai:u-ryukyu.repo.nii.ac.jp:02000800, author = {真壁, 朝敏 and 兼城, 英夫 and Makabe, Chobin and Kaneshiro, Hideo}, issue = {499}, journal = {日本機械学会論文集. A編, Transactions of the Japan Society of Mechanical Engineers. A}, month = {Mar}, note = {The growth behavior of a ductile crack resulting from a notch root was investigated in tensile tests of a center notched plate of low carbon steel S 15 CK. Four different notch root radii, ρ, that is, ρ=0.0 (crack) , 0.08, 0.14 and 0.25 mm were prepared for testing. It was found by measurement of strain, e, and the notch shape in tension, that the notch root was blunting in the same way, independent of the notch root radius, before ductile crack initiation, The crack grew with mixed mode fracture which combined tensile mode and shear mode fracture. In the growth process of the ductile crack, the crack growth rate, da/dε, for the strain increment is proportional to crack length, a, and the proportional constants of the da/dε-a relation take nearly the same values independent of the notch root radius. The crack opening angle, COA, decreases with crack growth., 論文}, pages = {503--508}, title = {S15CK中央切欠試験片の延性き裂進展とき裂開口状況の関係について}, volume = {54}, year = {1988} }