无端板矩形钢管混凝土构件基本剪切性能研究

该文进行了8个无端板矩形钢管混凝土构件基本剪切性能试验，考察了截面尺寸和剪跨比（0.3~0.8）对构件抗剪承载力及钢管和混凝土滑移的影响规律。结果表明:剪跨比为0.3时构件发生剪切破坏，随着剪跨比增大，构件破坏模式从剪切破坏逐步向弯曲破坏转化，并且随着剪跨比增大，构件抗剪承载力显著降低，核心混凝土滑移量也呈现减小趋势。同时，用有限元软件ABAQUS对试验结果进行了数值模拟，计算结果与试验结果总体上吻合良好，验证了建模方法的可靠性。在此基础上，研究了钢管与核心混凝土之间的摩擦粘结、构件有无端板及加载主轴方向对矩形钢管混凝土构件基本剪切性能的影响规律。表明钢管与混凝土接触面摩擦系数取0.25时与试验结果符合程度较好；端板对构件荷载-位移关系曲线屈服荷载无太大影响，但对曲线后期强化有一定影响；不同加载主轴方向对构件抗剪承载力有显著影响。

RESEARCH ON BASIC SHEAR PERFORMANCE OF CONCRETE FILLED RECTANGULAR STEEL TUBULAR MEMBERS WITHOUT END-PLATE

The shear performance of 8 concrete filled rectangular steel tubular members without end-plate was tested. The influences of the section size and shear-span ratio (0.3-0.8) on shear capacity and slip behavior were studied. The result indicates that the specimens experience shear failure when the shear-span ratio is 0.3. With the increasing of shear-span ratio, the failure pattern of the specimens changes from shear failure to bending failure, the shear capacity decreases, and the slip of core concrete decreases. The numerical simulation was carried out using ABAQUS, and the calculating results agree well with the test results in general. The model was verified by the tested results. The influences of parameters such as friction and bonding, with or without end-plate and different axial loading were investigated on the shear performance of the specimens. The results show that calculating results agree well with the test results when the friction coefficient is 0.25 in finite element model. The end-plate has a small effect on the yield platform of load-displacement curves, but it has a great effect on the strength of load-displacement curves. The axial load affects the shear capacity significantly.