The Study On Mechanical Properties Of Axial Compression Members Of Steel Structure Reinforced With FRP While Under Load

In recent years, steel components with superior mechanical properties are appliedmore and more widely in projects, and as part of the structural system, the mechanicalproperties of these will change with the time and external conditions. It occurs that thephenomenon of damage and aging in advance. So the reinforcement of the steel structure isnecessary.The study about the way of traditional steel reinforcement is relatively mature inChina. The achievements and application are embodied in Specification for design of steelstructures strengthened and detection and identification of steel structure reinforcementtechnology standard which were published in1996. But to the fiber reinforced by steelcomponents research has not listed in the relevant specification, and the research resultsabout the fiber reinforced steel structure component mostly did not consider the specificstress state of the original components capacity. There are a few literatures considered thestate of under load. The system study about the state of the stress of the original componentwas not appeared. Because these components are under load while they are reinforced, atthe same time the level of the under load of those components is diverse. In conclusion, itis necessary to the study of the strengthening of the steel while under different load states.The main work of this paper:From the study of12experimental short columns, the yield load, ultimate load and thefailure modes in the ultimate limit state were analysis in the parameters of different loadingpercentages, different strengthening modes and different layers. Test results that: with theincreasing percentage of under load, the yield load and ultimate load are decreased. Withthe increase of the layers of FRP, the ultimate bearing capacities of components increase.The effective of wrapped all the body is better than of wrapped the end of the columns, theeffective of wrapped the end of the columns is better than of wrapped the middle of thecolumns. The effective of wrapped the end of the columns is better than of wrapped all the body in the factors of the fiber content and the improvement percentages of the ultimateload.Through the experimental phenomenon and analysis results, combined with thecalculation theory of thin-walled compression members in domestic and abroad, they arepresented in non sustained load and loading conditions, the calculation formula of ultimatebearing capacity of FRP strengthened steel structure with axial compression members ofcapacity, and the capacity calculation formulas and test results were compared to verify theavailability of capacity calculation formula.Test by steel material and constitutive relations fiber material, the12experimentalshort columns are analyzed by finite element software ABAQUS, the correctness of thefinite element model is verified. On this basis, for the initial components defect, holdingload percentage, reinforcement layers, thickness ratio and other parameters were analyzed,but also on the FRP reinforcement steel pipe column axial compressive long series ofparametric analysis.