Eccentric compression behavior of circular concrete-filled steel tubes reinforced with internal latticed steel angles

The eccentric compression behavior of the CFSTs reinforced with inner latticed steel angles was experimentally investigated, and test results, such as the load-displacement curves, load-strain curves, distributions of lateral deflection, and ultimate load, were obtained and analyzed. Test results showed the influence of the latticed steel angles on the ultimate load was not obvious when the steel consumption was relatively small, and the lateral deformation was not obvious when the compression load was smaller than 80% of the ultimate load. The corresponding finite element (FE) model was established and validated by the test results, and parametric analysis was also conducted subsequent to validation. The analysis results showed the contribution of latticed steel angles to the ultimate load would be diminished as the eccentric distance increases. Moreover, the design equations for the ultimate load were proposed based on the FE results, and the calculation results indicated the proposed design equations can predict the ultimate load conservatively and safely.