考虑滑移影响的钢-混凝土组合梁的刚度

按照《钢结构设计规范》（GB50017—2003）计算组合梁考虑滑移后的折算刚度时，会遇到栓钉数量增加，刚度反而下降的现象。本文提出了新的折算刚度表达式，引入了钢与混凝土的组合作用系数来表征钢和混凝土轴压刚度通过抗剪件的作用而形成的组合作用的程度，采用考虑滑移影响的组合梁计算理论，求出了均布荷载下简支梁挠度的表达式，得到精度很高的简化计算公式，考察了栓钉抗滑移刚度值的确定方法，通过简单的分析，本文提出了折减刚度的计算公式，并与试验结果对比。将本文公式与规范计算公式和试验结果的对比，建议公式的误差更小，且公式更加简单，物理意义更加明确。

Bending Stiffness of Steel-Concrete Composite Beams Considering Effect of Slip

In calculating deflection of composite beams,the Chinese Code for design of steel structures GB 50017-2003 uses a reduced bending rigidity to consider the effect of slip at the steel-concrete interface of a composite beam. An abnormality appears in the formula for the reduced rigidity:as the number of studs increases,the calculated rigidity decreases sometimes. This paper proposes a new expression for the reduced bending rigidity. A coefficient representing the degree of the composite action between concrete and steel is introduced. Deflection of composite beams is solved using the bending theory for composite beams,in which the effect of slip is exactly included. A simplified equation for the reduced stiffness is proposed. Slip stiffness of the interface is discussed and formulae are proposed depending on the stress level of the stud. Comparison with available tests is carried out,and better correlation is found for the proposed equation. Compared with the code equation,the proposed formula is simpler,easier to use,and has a more clear physical meaning.