应变率效应对钢筋混凝土柱的影响

Influence of Strain Rates on Reinforced Concrete Column

根据混凝土单轴动力特性试验,引入了应变率的影响,对规范给出的混凝土应力—应变关系表达式进行了修正;针对只考虑混凝土的动态特性和既考虑混凝土的动态特性、也考虑钢筋的动态特性这两种情况,利用修正的表达式对钢筋混凝土柱的动态特性进行了数值分析。结果表明,混凝土的动态特性对于大偏心柱的承载力影响很小,但对于小偏心柱的极限承载力影响显著;钢筋的动态特性对大、小偏心柱的极限弯矩和极限曲率都有明显的影响。本文还分析了柱的极限弯矩、极限曲率和极限轴力随偏心距变化的规律。

According to the uniaxial dynamic experimental results of concrete, stress-strain relationship of concrete given by design code of reinforced concrete is modified taking into account the effect of strain rates of concrete. Then dynamic characteristics of reinforced concrete column are studied using the modified expression. Two situations are considered： （1） only dynamic characteristics of concrete are considered （2） dynamic characteristics of concrete and steel are considered. The result of numerical analysis shows that dynamic characteristics of concrete have little effect on the limit moment of large .eccentricity column but have considerable effect on the limit moment of small eccentricity column. Nevertheless, dynamic characteristics of steel have obvious effect on limit moment and limit curvature of both large eccentricity column and small eccentricity column. At the same time, the change rule of limit moment, limit curvature and limit axial force varying with eccentric distance are also studied.