CFRP加固轴压方钢管短柱局部稳定承载力试验研究

Experimental study on local stability bearing capacity of axially compressed square steel tube short columns strengthened with CFRP

为探究CFRP加固轴压方钢管短柱局部稳定承载力,设计制作了24个不同宽厚比试件,分为A、B两组,试验通过静力加载分别研究了试件长细比、CFRP加固方向及其粘贴层数对CFRP加固方钢管短柱局部稳定承载力以及破坏模式的影响。研究结果表明:24个试件均是由于局部失稳而破坏;方钢管短柱宽厚比与长细比对其初始刚度影响较小,但随着方钢管短柱宽厚比的增加其延性有一定程度降低。当方钢管短柱长细比在7~28范围内时,随着长细比的增加,环贴加固的效果慢慢减弱,纵贴加固的效果慢慢增强;当长细比在23~25时,环贴加固与纵贴加固的试件极限承载力相同;当长细比大于25时,采用纵贴CFRP加固方式较好;当长细比小于23时,采用环贴CFRP加固方式较好。

To investigate the local stability bearing capacity of CFRP-reinforced axially pressed square steel tube short columns,a total of 24 specimens with different width-to-thickness ratios were designed and fabricated in two groups A and B.The effects of member slenderness ratio,CFRP reinforcement direction and the number of adhesive layers on the local stability bearing capacity and damage mode of axially pressed CFRP-reinforced square steel tube short columns were investigated by static loading test method.The results show that the type of instability of all specimens in groups A and B are local instability.The initial stiffness of the square steel tube short column is less affected by the width-to-thickness ratio and slenderness ratio during loading and the ductility of the column decreases with the increase of the width-to-thickness ratio.When slenderness ratio of square steel tube short column is 7~28,with the increase of slenderness ratio,the reinforcement effect of ring bonding decreases gradually,and the reinforcement effect of longitudinal bonding increases gradually.When slenderness ratio is 23~25,the ultimate bearing capacity of ring bonding is equal to that of longitudinal bonding.When slenderness ratio is greater than 25,longitudinal CFRP reinforcement is recommended.When slenderness ratio is less than 23,ring CFRP reinforcement is recommended.