带加劲肋方钢管混凝土柱的静力特性

方钢管内填混凝土柱(CFSTs)在现代建筑中的使用越来越广泛,与钢柱和混凝土柱相比,其材料性能和功效均有所提高。然而,尽管方钢管混凝土柱的屈曲特性优于中空钢管,由于局部屈曲,其外包钢管截面的高厚比仍受到限制。针对外包钢管带加劲肋的方钢管混凝土柱,提出了一些新的加劲肋形式。为评估这些加劲肋对方钢管混凝土柱力学性能的影响,并与传统加劲肋进行比较,该文对4个带不同加劲肋的方钢管混凝土柱和1个无加劲肋方钢管混凝土柱进行了试验。试验研究了材料的抗力、延性和失效模式等力学性能,为了对试样的综合性能进行预测和总结,也从理论上对这些力学性能进行了研究。为了解各参数对力学性能的影响,该文进行了数值模拟和大量的参数研究,相关学者的试验数据验证了数值分析结果的准确性。基于试验结果和以往的研究,提出了截面强度的设计建议。

Static Behaviors of Reinforcement-Stiffened Square Concrete-Filled Steel Tubular Columns

Square concrete-filled steel tubes (CFSTs) are gaining increasing usage in modern construction practice, offering improved mechanical properties and increased material efficiency compared with the individual steel and core concrete components. However, the cross-section slenderness of the encasing steel is, although more inflexible than a comparable hollow steel tube, restrained due to local buckling. A number of innovative kinds of reinforcement stiffeners have been put forward particularly for the square CFSTs with slender sections of encasing steel. To investigate the mechanical effect of the reinforcement stiffeners and compare them with traditional ones in practice, four square CFSTs welded with various reinforcement stiffeners and one reference CFST have been tested, and are presented in this paper. The mechanical behaviors such as the resistance, ductility and failure modes investigated during the test were also studied in the theoretical research, which was carried out to predict and further summarize the comprehensive properties of the specimens. A numerical analysis program was written and verified with related scholars’ experimental data, and extensive parametric analysis was conducted to investigate the influencing parameters on mechanical properties. Design recommendation for the cross-section strength has been put forward based on the test results and previous research.