Abstract
Based on recent results from fracture toughness testing at low temperatures first generation fracture mechanics design criteria for welded steel structures under Arctic conditions have been proposed. The criteria address steel structures with utilization up to 80% of general yielding and limited defect sizes. A proposal for how to account for geometry constraint effects has been included, and is presented in the paper. Further, guidance on how to establish the characteristic fracture toughness and requirements to fracture toughness testing is also discussed. The effect of temperature on tensile properties is briefly presented. The main challenges in developing the model further are addressed at the end of the paper.