轴压力对钢筋混凝土悬臂柱水平侧移的影响

根据现行规范给出的预应力混凝土受弯构件短期刚度公式和普通受弯构件短期刚度公式,推导出了有轴力作用下和无轴力作用下的悬臂柱开裂弯矩、开裂前截面刚度和开裂后截面刚度的计算公式;在对钢筋弹性模量与混凝土弹性模量比、截面配筋率、截面有效高度和整截面高度比以及轴力大小等可影响轴力作用的一些参数因素进行分析的同时,得到这些因素对轴力作用的影响程度以及各因素间互相作用或制约的影响关系等定性规律。最后,通过悬臂柱的算例可发现,有些情况下,轴力对构件或结构的侧移可产生明显的有利影响。

Effect of Axial Pressure Force on Horizontal Displacement of Cantilever Column

On the basis of the short-term stiffness formulas provided by the current concrete codes for prestressed flexural member and normal flexural member,the formulas of cracking moment,pre-cracking section stiffness and post-cracking section stiffness for the horizontal displacement calculation of cantilever column which under axial force action and without axial force action are deduced.Some parameter factors which having effect on the axial force action are analyzed,such as the elastic modulus ratio of reinforcement and concrete,the ratio of reinforcement,the ratio of sectional effective height to sectional height,and the axial force values,then some qualitative regularities about the impact of foregoing parameters,the interaction relationship between foregoing parameters and axial force action are obtained at the same time.Finally,the results of cantilever columns show that axial force has a beneficial impact on the displacement of structure or member in some cases.