Abstract Concrete-filled steel tubular (CFST) truss with complex configurations are now widely used in practice, especially in large-scale bridge constructions. For such complex composite trusses, traditional structural analysis approaches are readily applied for the safety checks of individual members and connections, whilst inelastic analysis and reliability calibration are very limited. Recently, the development of advanced system-level analysis that takes into account various nonlinearities and uncertainties allows a rational reliability calibration for CFST trusses to assess their structural reliability. This paper aims to present reliability calibrations on three typical CFST trusses (two-chord, three-chord and four-chord) by advanced finite element models implemented with random uncertainties. The established finite element models are validated against experimental results. Afterwards, stochastic finite element analyses (FEA) are conducted taking into account the material and geometric nonlinearities, the random initial imperfections and the potential model errors. Using the obtained statistics of resistance, reliability calibration is then undertaken to calculate the reliability indexes of the three typical CFST trusses in respect of resistance factors under various load conditions, with the target reliability discussed in accordance with AASHTO and ANSI/AISC 360–16. The proposed novel computational approach and the reliability calibration contribute to both the practical design and the standard drafting for CFST trusses.

中文翻译：

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通过高级分析对多弦 CFST 桁架设计进行可靠性校准

摘要 结构复杂的钢管混凝土（CFST）桁架在实践中得到广泛应用，尤其是在大型桥梁建设中。对于这种复杂的组合桁架，传统的结构分析方法很容易应用于单个构件和连接的安全检查，而非弹性分析和可靠性校准非常有限。最近，考虑到各种非线性和不确定性的高级系统级分析的发展允许对 CFST 桁架进行合理的可靠性校准，以评估其结构可靠性。本文旨在通过使用随机不确定性实现的高级有限元模型对三个典型的 CFST 桁架（双弦、三弦和四弦）进行可靠性校准。建立的有限元模型根据实验结果进行验证。然后，考虑材料和几何非线性、随机初始缺陷和潜在模型误差，进行随机有限元分析 (FEA)。使用获得的阻力统计数据，然后进行可靠性校准以计算三种典型 CFST 桁架在各种负载条件下的阻力系数的可靠性指标，并根据 AASHTO 和 ANSI/AISC 360-16 讨论目标可靠性。所提出的新颖计算方法和可靠性校准有助于 CFST 桁架的实际设计和标准起草。考虑到材料和几何非线性、随机初始缺陷和潜在的模型误差，进行随机有限元分析 (FEA)。使用获得的阻力统计数据，然后进行可靠性校准，以计算三种典型 CFST 桁架在各种载荷条件下的阻力系数的可靠性指标，并根据 AASHTO 和 ANSI/AISC 360-16 讨论目标可靠性。所提出的新颖计算方法和可靠性校准有助于 CFST 桁架的实际设计和标准起草。考虑到材料和几何非线性、随机初始缺陷和潜在的模型误差，进行随机有限元分析 (FEA)。使用获得的阻力统计数据，然后进行可靠性校准，以计算三种典型 CFST 桁架在各种载荷条件下的阻力系数的可靠性指标，并根据 AASHTO 和 ANSI/AISC 360-16 讨论目标可靠性。所提出的新颖计算方法和可靠性校准有助于 CFST 桁架的实际设计和标准起草。然后进行可靠性校准以计算三种典型 CFST 桁架在各种负载条件下的阻力系数的可靠性指标，并根据 AASHTO 和 ANSI/AISC 360-16 讨论目标可靠性。所提出的新颖计算方法和可靠性校准有助于 CFST 桁架的实际设计和标准起草。然后进行可靠性校准以计算三种典型 CFST 桁架在各种负载条件下的阻力系数的可靠性指标，并根据 AASHTO 和 ANSI/AISC 360-16 讨论目标可靠性。所提出的新颖计算方法和可靠性校准有助于 CFST 桁架的实际设计和标准起草。