Engineering estimates of crack opening displacement for non-idealized circumferential through-wall cracks in pipe

•New h2 values of GE/EPRI method for circumferential non-idealized TWC are proposed.•New elastic CODs are proposed to predict COD of circumferential non-idealized TWC.•New COD estimate based on ERS method for circumferential non-idealized TWC is proposed.•The proposed estimates for CODs are validated against 3-D finite element results. The present paper provides the engineering estimates of non-linear crack opening displacement (COD) for a circumferential non-idealized through-wall crack in a pipe based on both the GE/EPRI and the enhanced reference stress methods. For the GE/EPRI-type solution, the h2 values are newly calibrated based on the elastic–plastic finite element analyses. Also, elastic COD and the reference load solutions are proposed. Then, the proposed engineering estimates are validated against the FE results using actual tensile data of SA312 Type 316 stainless steel. From these comparisons, it is revealed that the enhanced reference stress method provides the best and overall satisfactory results.