COD破壊基準による切欠付平板引張実験の検討 : 欠損を有する溶接接合部の破壊挙動に関する研究 その1

Abstract

The purpose of this paper is to determine the critical values of fracture of defective structural members after crack propagation based on the COD in non-linear fracture mechanics. In order to evaluate the deformation capacity of defective structure members which fractuer after crack propagation in according with the COD criterion, the COD and the overall strain ε_∞ were measured using notched plate specimens. The relationship between COD and ε_∞ becomes almost linear after the specimens turn fully plastic. However, as the crack propagates, the increment of COD increases until the linear relationship disappears, The value of COD at this point is assumed as the critical value of crack propagation δ_c. It can be seen that the δ_c value for a particular type of steel is almost constant regardless of the size of specimens. Therefore, it is thought that δ_c is an effective critical value for fracture behavior of steel members.