高圧ガスラインパイプ用厚肉・高靱性鋼管の脆性破壊伝播停止能とDWTT法

抄録

Drop Weight Tear Test is widely used as a testing method for evaluating the brittle crack arrestability of linepipe steels. Since this approach is originally based on the good correlation obtained between the results of full scale brittle propagation test and the shear appearance of DWTT, it is not clear if the same analogy could be applied for the recent large diameter and thick pipelines of newly developed steels.
In the present investigation, a trial is proposed to analyse the DWTT by the fracture mechanical method and to obtain the K_ca (fracture mechanical parameter for the brittle arrest) from the shear appearance of DWTT. It is possible to explain the design criterion of the transition theory (DWTT) by the design philosophy of the fracture mechanics.