Study Of Ultimate Bearing Capacity Of Hps Prestressed Beam And Column Members

As the main future field of engineering material in21stcentury, high performancesteel (HPS) can fit multiple demands for building structures, such as high strength,seismic resistance, environmental protection, weather resistance and easy process. Byconsulting a large number of international documents, this paper elaborated the basicconcept, sorts and significance of HPS, summarized its current situations in theoryresearch and engineering application, and put forward the problems to be improved.Then aiming at the shortcomings in recent study, HPS prestressed beam and columnmembers as the main research content is presented. Classification, characteristics anddevelopment of prestressed steel structure are briefly described.Failure modes of common beam and column members and prestressed membersare introduced, including overall buckling of column and beam, local buckling andstrength failure. The foundational theories and conclusions are also summed up.Combined with object of this paper, theoretical basis and approach of elementselection, boundary conditions, prestressing method in the process of finite elementanalysis modeling are illustrated. The solution methods and notes of buckling andnonlinear finite element analysis (with both mechanical and geometrical nonlinearities)used in the static analysis of ultimate bearing capacity are summarized.Then, after expounding the mechanism and classification of prestressed stayedcolumn, the analysis model for this work is determined. Through this, the elasticbuckling load and elastic-plastic stability bearing capacity are both analyzed, provingthat the stability and stiffness of steel column are improved obviously by prestressedcables system. On this basis, four factors affecting on the stability bearing capacity ofprestressed stayed column are investigated, namely the prestress level, steel type,residual stress and initial geometric imperfection.By the description of design and classification for prestressed I-beam, the analysismodel is proposed accordingly. The correctness of finite element model for commonI-beam and prestressed I-beam are verified. And the influences of prestress level, steelstrength and hybird HPS are mainly investigated on the failure models, bearingcapacity and deformation, through analysis of stability and bending bearing capacities for the two models.Finally some conclusions are drawn from above research results. Rationalcombination of prestress and HPS can highly increase the load-carrying behaviors forbeam and column components, take full advantages of both and complement eachother. When apply HPS for better carrying capacities, especially for the compressionmembers with a large slenderness ratio and the long span I-beams, a suggestion isgiven that adopt prestress technique to restrict the deformations.