Load-carrying Capacity Analysis Of Square Hollow Structural Section Columns Reinforced With FRP

Currently the theory of FRP used in the concrete structures and timber strengthening and retrofit is mature, however, only very limited theoretical analysis and experimental research has been conducted on the application of FRP composites to steel members. From at home and abroad research and application of FRP reinforcement used in the steel structure, mainly concentrated on flexural members, fatigue reinforcement and durability repair, FRP reinforcement of compression members are less. Use ANSYS finite element analysis as the main mean, the behaviors of axial loaded long cold-formed square hollow structural section (HSS) columns which strengthened by fibre reinforced polymer (FRP) plates are studied, emphatically to analysis the enhancing effect of FRP for bearing capacity of axial compressive square tube component.The mainly work of this paper is:Based on the analysis of the members key issues, the"shell-spring-shell"FEA model is proposed in the paper. The factors such as elastic-plastic behavior of steel, geometric nonlinearity, initial geometric imperfection and the FRP layers were considered in the finite element model. The model established by finite element analysis software ANSYS was effective by comparing the simulated and test results.By changing the initial bending of members, slenderness ratio and FRP paste layer, we discuss the influence of three parameters to the FRP reinforcement effect. Parameter analysis results indicate, the influence of members'intial bending and slenderness ratios to the FRP reinforcement effect are significantly, but while the layers of FRP increasing the bearing capacity has not improve obviously.In addition, ignoring the effects of adhesive layer, a numerical calculation model with simplified equivalent section was proposed. Calculate the stable bearing capacity of the simplified model by using Perry formula. Comparing the calculated results with finite element analysis results, The results show that most bearing capacity calculation and test results comply fine with finite element analysis. It can explain that the simplified model is practical. But part of the calculated values of the specimens'bearing capacity turns out not safe to use.Capacity correction coefficientωis given. And the bearing capacity of reference test specimen is caculated by using revised simplified model. Calculation results match well with the experimental data.