Abstract It has been well-recognized that high strength steels possess worse ductility and deformability compared to normal strength steels, leading to greater risk of low-cycle failure. In addition, high strength steels generally exhibit prominent cyclic softening behavior rather than cyclic hardening behavior. These characteristics should be properly implemented into finite element model to gain exclusive numerical simulation on cyclic behavior of high strength steel beam columns. In this paper, finite element models which not only consider the initial imperfection but also incorporate the ductile fracture behavior as well as cyclic softening behavior were established and used to simulate cyclic loading experiments on high strength steel beam-columns bending about strong axis. The simulation results including hysteretic curves and failure modes both provide good agreement with experimental results, verifying the capability of finite element models proposed. Accordingly, a parametric study was conducted to investigate the effects of axial load ratio, flange width-to-thickness ratio and web height-to-thickness ratio on cyclic behaviors of Q690 high strength steel beam-columns. It can be concluded that the increase in flange width-to-thickness ratio and axial load ratio will change the damage mechanism and consequently present different cyclic deterioration characteristics. Furthermore, the increase in flange and web slenderness and axial load ratio results in decrease in deformability and sectional plasticity development ability.

中文翻译：

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Q690高强钢梁柱循环性能数值研究

摘要 与普通强度钢相比，高强度钢的延展性和变形性较差，导致低周失效的风险更大，这一点已得到广泛认可。此外，高强度钢通常表现出显着的循环软化行为而不是循环硬化行为。应将这些特性适当地运用到有限元模型中，以获得对高强度钢梁柱循环行为的独家数值模拟。本文建立了既考虑初始缺陷又考虑了韧性断裂行为和循环软化行为的有限元模型，并用于模拟高强度钢梁柱绕强轴弯曲的循环加载实验。包括滞后曲线和失效模式在内的仿真结果与实验结果吻合良好，验证了所提出的有限元模型的能力。因此，进行了参数研究，以研究轴荷比、翼缘宽厚比和腹板高厚比对 Q690 高强钢梁柱循环行为的影响。可以得出结论，翼缘宽厚比和轴向载荷比的增加会改变损伤机制，从而呈现不同的循环劣化特征。此外，翼缘和腹板细长和轴向载荷比的增加导致变形能力和截面塑性发展能力的降低。验证所提出的有限元模型的能力。因此，进行了参数研究，以研究轴荷比、翼缘宽厚比和腹板高厚比对 Q690 高强钢梁柱循环行为的影响。可以得出结论，翼缘宽厚比和轴向载荷比的增加会改变损伤机制，从而呈现不同的循环劣化特征。此外，翼缘和腹板细长和轴向载荷比的增加导致变形能力和截面塑性发展能力的降低。验证所提出的有限元模型的能力。因此，进行了参数研究，以研究轴荷比、翼缘宽厚比和腹板高厚比对 Q690 高强钢梁柱循环行为的影响。可以得出结论，翼缘宽厚比和轴向载荷比的增加会改变损伤机制，从而呈现不同的循环劣化特征。此外，翼缘和腹板细长和轴向载荷比的增加导致变形能力和截面塑性发展能力的降低。翼缘宽厚比和腹板高厚比对Q690高强钢梁柱循环行为的影响。可以得出结论，翼缘宽厚比和轴向载荷比的增加会改变损伤机制，从而呈现不同的循环劣化特征。此外，翼缘和腹板细长和轴向载荷比的增加导致变形能力和截面塑性发展能力的降低。翼缘宽厚比和腹板高厚比对Q690高强钢梁柱循环行为的影响。可以得出结论，翼缘宽厚比和轴向载荷比的增加会改变损伤机制，从而呈现不同的循环劣化特征。此外，翼缘和腹板细长和轴向载荷比的增加导致变形能力和截面塑性发展能力的降低。