Study On The Influence Of T-shaped Rib Size On The Behavior Of GFRP-CFST Columns Under Axial Compression

FRP concrete steel tube composite column is a new type of composite column structural member composed of FRP outer pipe,inner steel pipe and concrete filled between two pipes,which is called DSTC column for short.DSTC column can make good use of the respective advantages of the three materials,and the ultimate bearing capacity and ductility of the members can be well balanced.In this thesis,the DSTC column is properly improved,and Tshaped ribs are welded and added on the outer wall of the inner steel pipe.The GFRP pipe reinforced concrete-filled steel tubular composite hollow column reinforced with T-shaped ribs is proposed for the first time.The relevant mechanical properties of the new structural form are studied through experiments.In this thesis,taking the height of T-shaped rib web,the width of T-shaped rib flange,the thickness of T-shaped rib and the reinforcement height of T-shaped rib as experimental variables,18 GFRP pipe-t-ribbed concrete-filled steel tubular composite hollow short columns and 2 GFRP pipe double tube confined concrete control columns are tested under axial compression.Record the failure mode of the specimen in the axial compression experiment,draw the typical mechanical property curve,and study the influence and change law of the four variables of T-rib web height,T-rib flange width,T-rib thickness and T-rib reinforcement height on the mechanical properties.Finally,combined with the data results of this experiment,the existing relevant design models are verified,the T-rib section replacement rate is introduced to modify the preliminary bearing capacity formula,the modified calculation formula of the ultimate bearing capacity of GFRP pipe-t-ribbed concrete-filled steel tubular composite hollow short column is proposed,and whether the formula and coefficient are applicable to the calculation of the ultimate bearing capacity of GFRP pipe-t-ribbed concrete-filled steel tubular composite hollow short column is verified,and the verification results are good,So as to provide a certain theoretical basis for the practical engineering application of the composite column component in the future.