Post-Fire Resistance of Titanium-Clad Bimetallic Steel Plate Girders Under Patch Loading

Abstract

Titanium-clad bimetallic steel (TCBS) is an ideal material for corrosive environments due to its excellent corrosion resistance. Fire poses a significant threat to TCBS plate girders, necessitating the evaluation of their residual capacity for repair and reinforcement after exposure to fire. However, research on the post-fire resistance of TCBS plate girders is lacking. A finite element modeling method was used to examine the residual capacity of TCBS plate girders after elevated temperature, whose accuracy was validated against experimental results. A parametric analysis involving 384 TCBS plate girder models was conducted, considering the effects of exposure temperature, cooling method, web geometry, and loading length. Based on numerical results, the design approach in EN 1993-1-5 was validated. Furthermore, a predictive formula for the buckling coefficient of the TCBS plate girder under patch loading was proposed, significantly enhancing the accuracy of buckling capacity calculation compared to EN 1993-1-5. Additionally, based on the resistance model in EN 1993-1-5 and the proposed formula for buckling coefficient, strength reduction functions for TCBS plate girders after various exposure temperatures and cooling methods were proposed. The research results provide an important basis for evaluating the residual bearing capacity of TCBS plate girders after fire.