CFRP板加固钢-混凝土组合梁的塑性承载力分析

Analysis of Plastic Carrying Capacity of Steel and Concrete Composite Girder Strengthened by CFRP Plate

推导了CFRP板加固钢-混凝土组合梁的塑性受弯承载力的计算公式,其中考虑了CFRP板拉断破坏和混凝土板压碎破坏2种破坏类型及3种不同塑性中和轴的位置。分析显示,对于CFRP板拉断破坏的情况,加固前的梁上负载以及预应力的作用对受弯承载力均没有影响;但对于混凝土板压碎破坏的情况,加固梁的受弯承载力随加固前梁上负载的增加而减少,随预应力的增加而增加。

The calculation formulae for carrying capacity of the steel and concrete composite girder strengthened by CFRP plate subjected to plastic bending are derived, in which two kinds of the failure of tensioning breaking of the CFRP plate and crushing of concrete slab and three kinds of different plastic neutral axis positions are considered. The analysis reveals that for the failure of the tensioning breaking of the CFRP plate, the load and prestressing action on the girder before it is strengthened has no influence on the bending capacity. However, for the failure of the crushing of the concrete slab, the bending capacity of the strengthened girder will decrease with the increase of the load on the girder before it is strengthened and will increase with the increase of the prestressing.