Study on the mechanical performance of self-stressing concrete-filled steel tube short column under cure bending

Abstract：Flexure tests on 12 self-stressing concrete filled steel tube (SSCFST) specimens and 3 conventional concrete filled steel tube (CFST) specimens were done.The results indicate that the flexural capacity of CFST specimen is lower than that of SSCFST specimen when 28-day cube strength of concrete core, yield strength and geometrical dimension of the steel tube are kept same.Based on a bounding surface model of the concrete and elastic-plasticity constitutive relations of steel, the finite element model of the self-stressing concrete filled steel tube is established, and the analysis on the mechanical performance is done.The calculated results indicate that the SSCFST specimen has higher carrying capacity than CFST specimen duo to self-stress.Finally, an empirical equation for predicting the shear capacity of SSCFST short beam is proposed.

Keyword：self-stressing;concrete filled steel tube;finite element model;flexure performance;carrying capacity;