Fan Jinglin, Lyu Fei, Ding Faxing, Bu Dan, Wang Siqing, Tan Zhongkun, Tan Sui
School of Architecture and Art, Central South University, Changsha 410075, China.
School of Civil Engineering, Central South University, Changsha 410075, China.
Materials (Basel). 2021 Aug 26;14(17):4839. doi: 10.3390/ma14174839.
Numerous studies have been carried out on the axially loaded circular concrete-filled steel tube (CCFST) stub columns. However, to date, no clear evaluation criterion for the compatibility of its design parameters has been established. In the present study, the compatibility of the design parameters (concrete compressive strength fc, steel yield strength fy, diameter and thickness of steel tube ) of axially loaded CCFST stub columns was quantitatively investigated in terms of the contribution of the composite actions to the axial bearing capacity of the columns. The composite ratio λ was proposed as an indicator to represent the effectiveness of the composite actions. A numerical framework of the determination of λ was established, making use of a series of existing widely recognized constitutive models of structural steel and concrete. Some modifications were carried out on these models to ensure the numerical stability of the presented analysis. Moreover, the rationality of the combined use of these models was verified. The analytical results show that excessive or very small D/t ratio should be avoided in design. Meanwhile, the combined use of low-strength steel and high-strength concrete should be avoided. A table of optimal D/t ratios corresponding to different material strength matches was provided for designers. Finally, an optimization of the design parameters using the proposed method and the existing design specification was performed.
针对轴压圆钢管混凝土短柱，已开展了大量研究。然而，迄今为止，尚未建立关于其设计参数协调性的明确评估标准。在本研究中，从组合作用对柱轴向承载力的贡献方面，对轴压圆钢管混凝土短柱的设计参数（混凝土抗压强度fc、钢材屈服强度fy、钢管直径和壁厚）的协调性进行了定量研究。提出组合比λ作为表征组合作用有效性的指标。利用一系列现有的、广泛认可的结构钢和混凝土本构模型，建立了确定λ的数值框架。对这些模型进行了一些修正，以确保所提分析的数值稳定性。此外，还验证了这些模型联合使用的合理性。分析结果表明，设计中应避免过大或过小的D/t比。同时，应避免低强度钢材与高强度混凝土的联合使用。为设计人员提供了对应不同材料强度匹配的最佳D/t比表格。最后，采用所提方法和现行设计规范对设计参数进行了优化。
