Abstract To investigate the seismic behavior of corroded steel frames in chloride environment, accelerated corrosion tests and lateral low cyclic loading tests were carried out on four steel frames. Firstly, a deterioration model of mechanical property with mass loss rate for corroded Q235B steel was proposed. Then, the failure process and mechanism of test steel frames were observed, the strain developments of potential plastic hinge sections at beam ends and column bases were analyzed, and the effects of corrosion level on the hysteretic curves, bearing capacity, stiffness degradation, ductility and energy dissipation capacity were studied in detail. The test results indicated that in relatively slight corrosion level, all specimens exhibited a hybrid yield dissipation mechanism, with the “beam end - column bottom - beam end” sequence of the plastic hinges occurring. However, an increase in corrosion level tended to accelerate plastic hinge formation and aggravate structural damage degree. Additionally, with the increase of corrosion level, the lateral bearing capacity reduced, stiffness degradation intensified, ductility and energy dissipation capacity decreased. Base on test data, the structural performance levels and performance index quantified thresholds of corroded steel frame were preliminarily determined. Moreover, a finite element model adopting a time-varying constitutive model of corroded steel and a stress triaxiality dependent failure criterion, was established using ABAQUS, and then verified to be valid by comparing the numerical and experimental results. The research results lay an experimental and theoretical foundation for the seismic performance evaluation of in-service steel frame structures in chloride environment.

中文翻译：

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氯化物环境下锈蚀钢框架抗震性能试验与数值研究

摘要 为研究腐蚀钢框架在氯化物环境中的抗震性能，对4个钢框架进行了加速腐蚀试验和横向低循环载荷试验。首先，提出了腐蚀Q235B钢力学性能随质量损失率的劣化模型。然后，观察了试验钢框架的破坏过程和机理，分析了梁端和柱底潜在塑性铰截面的应变发展，以及腐蚀水平对滞回曲线、承载力、刚度退化、延性和延性的影响。能量耗散能力进行了详细研究。测试结果表明，在相对轻微的腐蚀水平下，所有试样都表现出混合屈服耗散机制，随着塑性铰的“梁端-柱底-梁端”顺序发生。然而，腐蚀程度的增加往往会加速塑性铰的形成并加剧结构的破坏程度。此外，随着腐蚀程度的增加，横向承载能力降低，刚度退化加剧，延性和耗能能力下降。根据试验数据，初步确定了锈蚀钢框架的结构性能等级和性能指标量化阈值。此外，利用ABAQUS建立了采用腐蚀钢时变本构模型和应力三轴性相关破坏准则的有限元模型，并通过数值和实验结果的比较验证了其有效性。