配筋薄壁圆钢管混凝土短柱轴压极限承载力解析解

Analytical solution of axial ultimate bearing capacity for thin-walled steel columns filled with bar-reinforced concrete

为了研究配筋薄壁圆钢管混凝土短柱在轴压荷载作用下的力学性能,采用统一强度理论和薄壁圆筒理论,考虑中间主应力效应、材料SD效应(材料拉压强度异性)及箍筋有效约束面积的影响,推导了配筋薄壁圆钢管混凝土短柱的轴压极限承载力公式。通过算例计算并与其他承载力公式对比分析,验证了本文所推公式的正确性,研究了中间主应力、径厚比和材料拉压比对构件轴压极限承载力的影响。研究结果表明,本文建立的计算公式具有较高的计算精度,可以预测配筋薄壁圆钢管混凝土短柱轴压极限承载力的上、下限值,并包含了一系列基于不同强度准则的承载力解。本文计算方法具有较广泛的适用性,可为配筋圆钢管混凝土短柱力学性能的研究提供借鉴。

To study the mechanical property of thin-walled steel columns filled with bar-reinforced concrete under axial load, a computational formula of axial ultimate bearing capacity was deduced according to the unified strength theory and the thin-walled cylinder theory. Influences of some factors were considered specially in this formula,including the intermediate principle stress, the SD effect （strength-differential property of materials） and the effective hoop confinement of stirrup. By comparing with other computational formulae, the validity of the established formula was verified. Moreover, the influence characteristics of such factors were discussed as the intermediate principle stress,the diameter-thickness ratio and the tension-compression ratio. The research results indicate that the formula presented herein is of high accuracy. Both the upper and lower limits can be predicted by this formula, and a series of bearing capacity solutions based on different criteria are included in it. The computing method in this article is much broader applicable and may provide references for the follow-up studies of steel columns filled with bar-reinforced concrete.