Analysis of the brittle fracture avoidance model for pressure vessels in European standard

Abstract A procedure for design against brittle failure based on a fracture mechanics model is available in the recent European pressure vessel standard EN 13 445. In the present paper, this model is analysed in the light of more recent findings in fracture mechanics. In particular, results from the SINTAP project and the Eurocode 3 procedure for selection of steel to avoid brittle fracture are considered. Alternative models for the scatter in strength, fracture toughness—impact toughness correlations as well as their temperature dependence, thickness dependence and strain rate dependence are compared. Different approaches for the handling of residual stresses are discussed. When the effect of elasto-plastic corrections is taken into account both for primary and secondary stresses, the net effect is small. In relation to more recent findings, the models used as a basis for EN 13 445 seem somewhat conservative, in particular for thinner gauges.