HOLLOW STEEL STRUCTURE HAVING EXCELLENT BRITTLE FRACTURE CHARACTERISTIC AFTER PLASTIC BUCKLING

摘要

PROBLEM TO BE SOLVED: To provide a hollow steel structure having excellent brittle fracture characteristic after the plastic buckling which uses steel having high brittle fracture occurrence preventive characteristic and high strength of a surface layer part capable of preventing brittle fracture of the steel structure at relatively low cost.;SOLUTION: In the hollow steel structure having excellent brittle fracture characteristic after the plastic buckling consisting of steel having the thickness of ≥ 20 mm, face and back side surface layer parts of the thickness of ≥ 2 mm to satisfy the inequalities (A) and (B) are excellent in the brittle fracture occurrence preventive characteristic so that the brittle fracture does not occur even after representing the maximum load by the standard fracture toughness test in compliance with ISO 12737 at the temperature lower by 120°C than the minimum service temperature, and the yield stress in the face and back side surface layer parts of steel satisfy the inequality (C). Inequalities (A): 0c0.375, (B) 0.5(1-1/b)c0.5(1-b/1.05)/(1-b), and (C) 1.05b4, respectively, where c is the ratio of the thickness from the face and back side faces to the total thickness, and b is the ratio of the yield stress in the face and back side surface layer parts to the yield stress in a center portion of steel.;COPYRIGHT: (C)2006,JPO&NCIPI