Experimental and numerical investigation on patch loading capacity of longitudinally stiffened hybrid titanium-clad bimetallic steel plate girder

Plate girders are important load-bearing components of bridge and industrial structures. Corrosion significantly affects durability and service life of plate girders. Bimetallic steel consisting of corrosion-resistance metal and metal with superior mechanical properties provides an engineering solution for the mitigation of corrosion. The titanium-clad bimetallic steel (TCBS) was innovatively introduced into the plate girder as the web to solve the corrosion issue, where the nonlinear resistance performance and failure mode of a longitudinally stiffened hybrid TCBS plate girder under patch loading were investigated experimentally. The test results prove that the longitudinally stiffened hybrid TCBS plate girder has stable load-bearing performance, which is similar to that of the conventional mild steel plate girder. Effects of the shape and magnitude of the initial geometric imperfection on the resistance behavior of the longitudinally stiffened hybrid TCBS plate girder were investigate numerically. A parametric study on the effects of the material properties, longitudinal stiffener location, relative flexural rigidity of the longitudinal stiffener, web panel aspect ratio, and web height-to-thickness ratio on the resistance and critical buckling behaviors of a longitudinally stiffened hybrid TCBS plate girder was performed. Considering the strain strengthening properties of TCBS, the ultimate resistance and ductility of longitudinally stiffened hybrid TCBS plate girders can be significantly improved without affecting the buckling performance. The effect of key parameters on the longitudinally stiffened hybrid TCBS plate girder is consistent with that of the conventionally stiffened mild steel plate girder. Therefore, it is a feasible solution to apply TCBS to the plate girder web, which performs a beneficial effect on the durability of the plate girder.