朱经纬, 王春生, 翟晓亮. 圆管翼缘钢-混凝土新型组合梁负弯矩区力学性能试验研究[J]. 工程力学, 2018, 35(12): 124-133. DOI: 10.6052/j.issn.1000-4750.2017.09.0712
引用本文: 朱经纬, 王春生, 翟晓亮. 圆管翼缘钢-混凝土新型组合梁负弯矩区力学性能试验研究[J]. 工程力学, 2018, 35(12): 124-133. DOI: 10.6052/j.issn.1000-4750.2017.09.0712
ZHU Jing-wei, WANG Chun-sheng, ZHAI Xiao-liang. EXPERIMENTAL RESEARCH ON THE MECHANICAL PROPERTIES OF STEEL AND CONCRETE COMPOSITE GIRDERS WITH CIRCLE TUBULAR UP-FLANGE UNDER NEGATIVE BENDING[J]. Engineering Mechanics, 2018, 35(12): 124-133. DOI: 10.6052/j.issn.1000-4750.2017.09.0712
Citation: ZHU Jing-wei, WANG Chun-sheng, ZHAI Xiao-liang. EXPERIMENTAL RESEARCH ON THE MECHANICAL PROPERTIES OF STEEL AND CONCRETE COMPOSITE GIRDERS WITH CIRCLE TUBULAR UP-FLANGE UNDER NEGATIVE BENDING[J]. Engineering Mechanics, 2018, 35(12): 124-133. DOI: 10.6052/j.issn.1000-4750.2017.09.0712

圆管翼缘钢-混凝土新型组合梁负弯矩区力学性能试验研究

EXPERIMENTAL RESEARCH ON THE MECHANICAL PROPERTIES OF STEEL AND CONCRETE COMPOSITE GIRDERS WITH CIRCLE TUBULAR UP-FLANGE UNDER NEGATIVE BENDING

  • 摘要: 为研究圆管翼缘组合梁负弯矩区的力学性能,进行了5根简支组合梁负弯矩作用下的静力加载试验,分析了试验梁的变形、应变发展规律。依据试验梁承载能力极限状态下的受力特性,采用简化塑性理论推导了圆管翼缘组合梁负弯矩区纯弯、纯剪承载力的计算公式,比较了公式对试验梁极限承载力的计算精度。对比EC4、GB 50917-2013、ASCE及Liang等公式的弯剪相关关系及对试验梁极限承载力的计算结果,提出了圆管翼缘组合梁负弯矩区弯剪相关承载力的适用计算公式。研究结果表明:试验梁在试验过程中表现出良好的稳定性和延性性能,最终破坏时伴随发生了局部剪切屈曲、下翼缘侧向屈曲、梁端腹板压屈及钢梁整体弯扭屈曲等4种典型破坏形态;当混凝土翼板受拉开裂后,不计混凝土抗剪作用的计算弹性剪应变分布较为符合实测剪应变曲线;受高剪力、高弯矩相关效应影响,计算负弯矩区圆管翼缘组合梁承载力时应考虑弯剪相关作用;GB 50917-2013给出的弯剪相关关系对试验梁极限抗弯承载力的计算平均值为96%,是综合计算精度与结果安全性的较适用公式。建议在应用所提纯弯、纯剪承载力公式的基础上,采用GB 50917-2013的弯剪相关公式计算负弯矩区圆管翼缘组合梁的弯剪相关承载力。

     

    Abstract: In order to investigate the mechanical properties of steel and concrete composite girders with circle tubular up-flange in negative moment region, five simply supported composite girders under negative moment were tested by static loading. According to the characteristics of test girders at the strength limit state, the formulas for the ultimate moment capacity in pure bending and the ultimate shear strength in pure shear for circle tubular up-flange composite girders under negative moment were developed based on the simplified plastic theory, which were then compared with the experimental results to evaluate the calculation precision. The moment-shear (M-V) interaction from EC4, GB 50917-2013, ASCE specifications and the formulas proposed by Liang et al. as well as the corresponding predictive values of ultimate strength were compared, and an applicable form of M-V interaction was found to well estimate the M-V strength interaction for circle tubular up-flange composite girders in negative moment region. The results indicate that the test girders show excellent stability and ductility during loading. Four typical failure modes, including local shear buckling, lateral buckling of the lower flange, web crippling at the end of test girders and lateral flexural-torsional buckling of the steel beam, take place together in the last damage state. After the concrete slab crack in tension, the calculated elastic shear strain distribution without consideration of the contribution from the concrete slab agrees well with the measured shear strain curves. Furthermore, the M-V interaction should be considered in calculating the ultimate strength of circle tubular up-flange composite girders in the negative moment region due to the influence of high-shear and high-moment. The M-V strength interaction from GB 50917-2013, with the average accuracy of 96% compared with the test values, provides the best combination of accuracy and safety of prediction. Based on the application of formulas for the ultimate moment capacity in pure bending and the ultimate shear strength in pure shear proposed by this paper, it is suggested that the M-V strength interaction according to GB 50917-2013 should be used to calculate the ultimate strength of circle tubular up-flange composite girders under negative moment.

     

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