RESIDUAL STRESS STUDY ON WELDED SECTION OF HIGH STRENGTH Q460 STEEL AFTER FIRE EXPOSURE

摘要

The residual stress magnitude and distribution of mild carbon steel sections at room temperature has been widely studied. Little investigation has been performed on residual stress of high strength steel sections, especially at elevated temperatures and after fire exposure. The fire exposure and elevated temperature have great influence on the residual stress distribution. This paper presents the experimental study of residual stress of welded high strength steel H-shaped section after fire exposure. The residual stress at room temperature was compared with that after fire exposure both for mild steel and high strength steel. The residual stress of welded high strength Q460 steel section was also simulated by finite element analysis and the validated finite element model was employed to analysis the residual stress of high strength steel section at elevated temperatures. It is found that the residual stress of high strength steel section after fire exposure decreases significantly and the residual stress variation should be considered on fire resistance design of high strength steel structures.