部分包覆钢-轻骨料混凝土组合短柱轴压性能数值分析

为研究部分包覆钢-轻骨料混凝土组合(PELC)短柱的轴压性能,采用ABAQUS软件建立了轴压作用下部分包裹钢-轻骨料混凝土组合短柱的有限元模型。通过典型构件揭示了部分包覆钢-轻骨料混凝土组合短柱在轴压荷载作用下的全过程受力机理与破坏模式; 分析了轻骨料混凝土强度、系杆间距、含钢率以及翼缘宽厚比等参数对部分包覆钢-轻骨料混凝土组合短柱轴压性能的影响规律; 基于规范AISC 360并考虑轻骨料混凝土约束效应,提出了一种部分包覆钢-轻骨料混凝土组合短柱轴压承载力的计算公式。结果表明:部分包覆钢-轻骨料混凝土组合短柱在轴压荷载作用下的主要破坏模式为轻骨料混凝土压溃、H型钢正弦半波状鼓曲以及系杆屈服; 部分包覆钢-轻骨料混凝土组合短柱的极限承载力将随着轻骨料混凝土强度与含钢率的增加而提高,延性将随着含钢率的增加而提高,随着系杆间距和轻骨料混凝土强度的增加而降低; 研究结果将为轻骨料混凝土组合柱在实际工程中的设计与应用提供理论依据。

Numerical Analysis of Axial Compression Behavior of Partially-encased Lightweight Aggregate Concrete Composite Stub Columns

In order to investigate the axial compression behavior of partially-encased lightweight aggregate concrete composite(PELC)stub columns, the finite element analysis model of PELC stub column under axial compression load was established by the software ABAQUS. Through the analysis of typical members, the whole process stress mechanism and failure mode of PELC stub columns under axial compression were revealed. The effects of parameters such as lightweight concrete strength, tie bar spacing, steel ratio and flange width-thickness ratio on the axial compression behavior of PELC stub columns were analyzed. Based on AISC 360 and considering the restraint effect of lightweight aggregate concrete, a calculation method of axial compressive capacity of PELC stub column was proposed. The results show that the main failure modes of PELC stub column under axial compression are lightweight aggregate concrete crushing, H-shaped steel sinusoidal half wave bulging and tie bar yielding. The ultimate bearing capacity of PELC stub columns increase with the rise of the lightweight aggregate concrete strength and steel ratio, and the ductility increase with the improvement of steel ratio, and decrease with the rise of tie bar spacing and lightweight aggregate concrete strength. The research results will provide a theoretical basis for the design and application of lightweight aggregate concrete composite columns in practical engineering.