| 引用本文: | 吴丽丽,刘艳霞,武海鹏,韩港豪.L形冷弯薄壁型钢组合钢管混凝土柱轴压性能[J].哈尔滨工业大学学报,2025,57(1):77.DOI:10.11918/202309070 |
| WU Lili,LIU Yanxia,WU Haipeng,HAN Ganghao.Axial compressive performance of L-shaped concrete-filled cold-formed thin-walled steel tubular columns[J].Journal of Harbin Institute of Technology,2025,57(1):77.DOI:10.11918/202309070 |
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| 摘要: |
| 为解决异形钢管混凝土柱阴角对其承载力的影响,提出了用1个冷弯薄壁方钢管和2个U形钢管焊接成L形钢管,内填充混凝土形成L形冷弯薄壁型钢组合钢管混凝土柱形式。设计了5组共10根试件的轴压试验,并开展了有限元参数分析,研究了钢管厚度、U形管外伸长度和钢材强度等参数对构件承载力和延性等力学性能的影响。结果表明:该类试件的主要破坏形态为中上部局部鼓曲破坏,适量增大U形管外伸长度可以提高承载力,但增大到一定程度之后易发生弯扭破坏；承载力和延性随着钢管厚度和钢材强度增大而增加；混凝土强度对构件的初始刚度和峰值荷载的影响都很小,但对曲线下降段的影响较大； 试件端部和中部截面阴角处的混凝土应力值比各边中部更大,说明采用U形钢管与方钢管组合的方式改善了阴角处钢管对混凝土约束普遍较弱的问题。基于“统一理论”,给出了两种承载力建议计算公式,与试验结果吻合较好,两种计算方法在0.44~1.94的约束效应系数范围内具有良好的适用性。 |
| 关键词: L形 U形管 钢管混凝土柱 轴心受压 承载力 |
| DOI：10.11918/202309070 |
| 分类号:TU398 |
| 文献标识码:A |
| 基金项目:国家自然科学基金(7,4)；中国矿业大学(北京)越崎杰出学者奖励计划(2602021RC59) |
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| Axial compressive performance of L-shaped concrete-filled cold-formed thin-walled steel tubular columns |
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WU Lili,LIU Yanxia,WU Haipeng,HAN Ganghao
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(School of Mechanics and Civil Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China)
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| Abstract: |
| The study investigates the bearing capacity of specially shaped, concrete-filled steel tube columns, emphasizing the impact of reentrant corners. A novel design was proposed, involving the welding of one cold-formed, thin-walled square steel tube and two U-shaped steel tubes into an L-shaped configuration, which is then filled with concrete to form an L-shaped concrete-filled cold-formed thin-walled steel tubular columns. To explore this concept, a series of axial load tests were conducted on 10 specimens with total of 5 groups. These experiments were complemented by finite element analysis to assess the effects of various parameters, including steel tube thickness, protrusion length of the U-shaped tubes, and steel material strength, on the structural integrity and ductility of the columns. Results indicate that the predominant failure mechanism involved localized buckling in the upper-middle region. An increase in the U-shaped tubes protrusion length was found to enhance structural capacity up to a certain threshold, beyond which flexural-torsional failure becomes prevalent. Additionally, both the structural capacity and ductility of the columns were positively correlated with increases in steel tube thickness and material strength. The strength of the concrete was observed to have a minimal impact on the initial stiffness and peak load of the columns, yet significantly influenced the descending phase of the load-deflection curve. Moreover, concrete stresses were more pronounced at the reentrant corners of the specimen ends and mid-sections compared to the lateral mid-sections, suggesting an enhanced restraint by the combination of U-shaped and rectangular steel tubes in these regions. According to the“unified theory”, two sets of calculation formulas for loadbearing capacity were proposed. These formulas not only align closely with experimental results but also demonstrate robust applicability across a wide range of constraint effect coefficients, from 0.44 to 1.94. |
| Key words: L-shaped U-shaped tube concrete-filled steel tubular column axial compression bearing capacity |
