多室式钢管混凝土形构件纯弯力学性能研究

进行了4 个多室式钢管混凝土T形试件和2 个多室式空钢管T形对比试件的纯弯试验,着重研究前者在纯弯状态下的变形过程及破坏形态,同时考察了截面尺寸、加载位置等参数对其纯弯力学性能的影响.试验结果表明：增大截面腹板高度能显著提高多室式钢管混凝土T形试件的抗弯承载力;力分别作用在翼缘或腹板时其承载能力有一定的差异;试件的破坏形态以整体弯曲为主.采用有限元方法对多室式钢管混凝土T 形试件的弯矩-挠度曲线进行了全过程分析,与试验结果吻合较好.最后在参数分析的基础上提出了多室式钢管混凝土T形构件抗弯承载力的实用计算方法.

STUDY ON MECHANICAL PROPERTIES OF MULTI-CELL T-SHAPED CONCRETE FILLED STEEL TUBES SUBJECTED TO PURE BENDING

4 multi-cell T-shaped concrete-filled steel tubes (MT-CFST) and 2 multi-cell T-shaped steel tubes (MT-ST) subjected to pure bending were tested. The failure modes and the effects of cross-section dimensions and loading position on pure bending behaviors of MT-CFST specimens were examined as well. It was found in the experiment that the flexural capacities of MT-CFST specimens can be significantly enhanced by increasing the web height. The loading capacity was different when the force acted on the flange or the Web. Failure modes were mainly overall bending. Subsequently the finite element method is used to calculate the moment-deflection relationships of the MT-CFST specimens. The calculated curves show good agreement with the presented test results. Based on the parametric analysis, a simplified formula for calculating the ultimate strength of the new type of composite members under pure bending is recommended in the end.