RESEARCH ON MECHANICAL PROPERTIES OF AXIALLY LOADED TUBULAR STEEL STUB COLUMNS REINFORCED BY CFRP

The paper investigated the behavior of axially loaded tubular steel stub columns reinforced by CFRP (carbon fiber reinforced polymer) through experimental study, finite element modelling and theoretical analysis. The mechanical properties of reinforced members were studied by changing the initial load level and the paste way of CFRP. Then the influences of initial load level and paste way of CFRP on the ultimate bearing capacity and failure mode of reinforced members were discussed. Through experimental study, finite element simulation and parameter analysis, it was found that the ultimate bearing capacity of reinforced members decreases with the increasing of initial load. And the reinforced members mainly fail into local buckling at the end of tubular steel stub columns. The reinforcing effect of paste CFRP at the end of columns is better than that at the middle of columns. With the increasing of CFRP reinforcement layers, the ultimate bearing capacity increases. However, the increasing percentage decreases after it reaches a certain level. With the increasing of the thickness of tubular steel stub columns, the influences of the initial load level and CFRP layer decrease. A comparison among the results of experimental study, theoretical analysis and finite element simulation shows that the theoretical formulas proposed in this paper can be used to calculate the bearing capacity of axially loaded tubular steel stub columns reinforced by CFRP.