@article{oai:repo.lib.tut.ac.jp:00001247, author = {山田, 伸弥 and 小林, 俊郎 and YAMADA, Shinya and KOBAYASHI, Toshiro}, issue = {555}, journal = {日本機械学會論文集. A編, Transactions of the Japan Society of Mechanical Engineers. A}, month = {Nov}, note = {In the present study, crack extension behavior and fracture toughness of ductile cast iron are examined by three-point bending tests with various detection methods of crack initation under static and dynamic loading conditions. Loading on specimens is interrupted at various displacement points, and fracture surfaces of the specimens are observed by scanning electron microscopy (SEM). Each method is effective in detecting the strict crack initiation at the middle of specimen thickness under static and dynamic loading conditions. J (mid) is proposed to define the fracture toughness of ductile cast iron. Crack tip opening displacement(CTOD) under the dynamic loading condition is smaller according to the results of calculation and SEM observation. It is considered that crack initiation under the dynamic loading condition is accelerated since the plastic deformation cannot follow up deflection of the specimen., ・rights:日本機械学会 ・rights:本文データは学協会の許諾に基づきCiNiiから複製したものである ・relation:isVersionOf:http://ci.nii.ac.jp/naid/110002371273/}, pages = {2088--2093}, title = {球状黒鉛鋳鉄における静的および動的破壊靱性の評価}, volume = {58}, year = {1992} }