To study the seismic behavior of corroded steel frame beam-column joints in acid atmosphere, the hysteretic behavior of 6 steel frame beam-column joints with different degrees of corrosion were investigated experimentally, which have been damaged by the different acid salt spray corrosion cycles under low cyclic reversed loading. The test results show that as the corrosion degree increases, the mechanical and seismic properties of the specimen such as strength, stiffness, ductility and hysteretic energy are deteriorating. In addition, the restoring force model of the rusted steel frame beam-column joints was studied. Based on the test results, the formula of the characteristic points of the skeleton curve of steel frame beam-column joints with corrosion was obtained, which considered the steel corrosion rate. The cyclic degradation index based on hysteretic energy loss was introduced, and the hysteresis rule applied to steel frame joint specimens after corrosion cycles were proposed, and then restoring force model of corroded steel frame beam-column joint was established, which considered the strength and stiffness degradation. And then, the applicability of the model was verified. The results show that the proposed hysteretic model can desirably reflect the hysteretic behavior of corroded steel frame beam-column joints. This study may provide theoretic basis for elastoplastic analysis of existing steel structures in acid atmospheric environment.
