Experimental and numerical investigation on seismic performance of corroded welded steel connections

The objective of this work is to investigate experimentally and numerically the effect of neutral salt-spray corrosion damage on the seismic capacity of welded steel connections. Firstly, the surface morphology characteristics and mechanical properties of corroded steel were discussed by testing the standard specimens fabricated from the welded connections with different exposure corrosion time. Then, the inelastic cyclic loading tests of 4 deteriorated connection specimens with different corrosion damage degrees were conducted to evaluate the changes of cyclic behavior and failure mode. Test results showed that the bearing capacities and the stiffness of corroded connections decreased due to the sectional area losses of the beam and the column, while the existence of severe pits in the welded zone accelerated the brittle fracture failure of corroded beam flange, resulting in the significant degradations of ductility and total energy dissipation. In addition, a series of parametric numerical simulation was performed to analyze the effects of different corrosion parameters on the seismic performances of connections. Analytical results indicated that the larger value could be chosen from the beam flange corrosion and the column web corrosion to estimate the remaining ultimate bearing capacity of existing connections, while the pitting damage and the uniform corrosion on the beam flange could be regarded as the main factors affecting the degradation degree of deformation capacity and energy dissipation capacity.