Experimental Study On Stable Bearing Capacity Of Compressed Square Steel Tube Strengthened By CFRP Under Load

Compared with the technical field of concrete strengthening with CFRP,the research and application of steel structure strengthening with CFRP is still insufficient.The steel structure strengthened by CFRP has the advantages of good reinforcement effect and convenient construction,so it is the focus of domestic and foreign scholars.At present,the research on the ultimate bearing capacity of steel tubular columns strengthened with CFRP at home and abroad is mainly focused on the bearing capacity of steel tubular columns strengthened with CFRP under the condition of no initial stress.The experimental and theoretical research considering the effects of eccentric pressure,load-bearing and structural measures is not sufficient,and a complete theoretical system and reinforcement design method have not yet been formed.The main contents of this paper are as follows:(1)On the basis of summarizing and comparing the research results of domestic and foreign scholars,seven groups of strengthening members with two layers of carbon fiber cloth are designed to carry out stability test,and the test results of failure characteristics,stress-strain distribution characteristics and ultimate bearing capacity of the test members are studied.Combined with the section change algorithm and the current steel structure design standards in China,the limit of compression bending members is proposed The bearing capacity formula compares the calculated value with the test value.(2)Select reasonable parameters such as material properties,element types,mesh division and boundary conditions,establish the same finite element model as the test specimen,carry out numerical simulation analysis of the stability of the eccentric pressure steel tube column under the condition of load holding,and compare the numerical simulation results with the test results to verify the reliability and accuracy of the model.(3)On the basis of the relevant formulas in the current steel structure design standard,through the fitting of simulation data,this paper puts forward the modified calculation formula of the stable bearing capacity of the compression members strengthened by CFRP under the condition of load holding,which can be used as a reference for the design of the stable bearing capacity.