MECHANICAL PROPERTY ANALYSIS ON AXIALLY COMPRESSED CONCRETE FILLED CIRCULAR CFRP-STEEL TUBE STUB COLUMNS

Mechanical property of axially compressed concrete filled circular CFRP-steel tube stub columns is analyzed based on experimental results.The working mechanisms of the composite column at different stages are analyzed and the stress paths in concrete,steel and CFRP are given.The stress-strain relationship of the axially loaded composite column is then determined,which is divided into 4 stages:elastic,elasto-plastic,strengthening and softening.Compared with that of concrete filled circular steel tube stub column,the axial stress-strain relationship of the composite column investigated exhibits an obvious strain softening after the peak strength is reached.The simplified analysis methods of ultimate strength are finally discussed and the method of limit equilibrium is recommended.