抄録
In this paper, for the Use of Material Grades for Hull Structural Members in NK Rule, the allowable crack lengths (the minimum values of crack lengths regarded as allowable) of each grade plates are estimated, corresponding to the critical plate thicknesses at 0℃ (the lowest service temperature specified in NK Rule). It is obvious that these values quite differ. Here, as authors' proposal, a use of material grades for hull structural members is presented, so that the allowable crack lengths corresponding to the critical plate thicknesses at 0℃ are about same.
