U字切欠きを有する脆性材料のモードI破壊クライテリオンに関する研究

抄録

Over the decades, vast numbers of technical papers and reports have focused on fracture, and a number of fracture criteria have been proposed and published. In this study, a new fracture criterion which satisfies the necessary stress and energy conditions progressively was proposed for brittle materials. This method is based on the assumption that fracture is mainly generated by the initiation of a crack with finite length 1_cm. Also, in our proposed criterion, it is assumed that the crack length 1_cm is an intrinsic material parameter, and exists between 0.8d_0m ≤ 1_cm ≤ d_0m . The exact value of the crack length 1_cm should be discussed through a number of experimental tests. However, in this study, three typical cases of the crack length 1_cm=0.8d_0m, 1_cm=0.9d_0m and 1_cm=d_0m, and the estimated values of the fracture load were compared with experimental results. The predicted values of ultimate stresses based on the required stress and energy conditions agree well with experimental data for brittle materials under the condition of 1_cm=0.9d_0m.