滑移效应对钢-混凝土组合梁弯曲强度的影响及其计算

SLIP EFFECT ON STRENGTH OF COMPOSITE STEEL CONCRETE BEAMS

在采用栓钉等柔性抗剪连接件的钢-混凝土组合梁的交界面上存在相对滑移变形,它不仅使梁的挠度增大,而且还使组合梁截面的弹性抗弯强度减小,现行换算截面法尚未考虑这一不利影响.本文通过滑移效应对组合梁抗弯强度影响的试验和分析,建立了考虑滑移效应的弹性和极限抗弯强度计算公式.结果表明,考虑滑移效应的弹性弯矩计算值与实测值吻合较好.考虑强度极限状态时钢梁部分截面进入强化阶段的有利影响,滑移对极限抗弯强度的影响可以忽略不计,对于完全剪力连接和横向配筋率不小于0.6%的组合梁,按照简化塑性理论的等效矩形应力模型得到的极限抗弯强度计算值与实测值吻合良好.

The effect of slip existing at the interface of steel and concrete in composite steel-concrete beams with flexible stud connectors decreases elastic flex-Ural strength and increases deformation of the beams, yet it is not taken into account in the current transformed section method. In this paper, experimental investigation and analysis have been conducted on the effect of slip on flexural strength of composite beams. Expressions for predicting flexural strength in consideration of slip effect are proposed. The predicted values of elastic flexural strength are in good consistent with the test results. It is shown that the effect of slip can be ingored on ultimate flexural strength due to the contribution of hardening of part of the steel section. Thus, the ultimate flexural strength can be determined by simple plastic theory.