Research On The Mechanical Property Of Concrete Filled Steel Tubular Laced Column

Concrete filled steel tubular (CFST) laced columns are widely used inengineering fields. However, the calculation method for the mechanicalproperties of CFST laced columns exis shortcomings and deficiencies up to now.The current design methods are mainly derived from research results of steellaced columns, and theoretical calculations often do not reflect the owncharacteristics of CFST laced columns, so the calculation results often exist largeerrors. Through theoretical analysis and simulation, this article has completed theresearches for the equivalent slenderness ratio of CFST laced columns underaxial compression, the mechanical properties of joints connecting the columnsand column webs, and the lateral properties of laced columns.According to the calculation formula for critical load considering the effectsof shear deformation and axial shortening, this article push es the calculationformulas of equivalent slenderness ratio based on the unified theory proposed byZhong Shantong. The calculation results of this formula is more accurate thanothers, and it solves the problems that shear deformation is too large for themembers of small slenderness ratio, and the calculation formulas in this articleare verified based on existing experimental results.This article has completed the research for the mechanical properties ofjoints connected limbs and webs. During the research, it has analyzed the impactsof joints on column limbs, and deduced a new formula for calculating theultimate bearing capacity of joints. The formula is based on the ring modelassumptions. The proposed capacity formula aims at the damage for columnlimbs.This article has completed the research for lateral properties of CFST lacedcolumns. It has revised and simplified the original reduction coefficient forstiffness, and got the new stiffness reduction factors for flat belly bars andoblique webs. During the derivation process, element that compression andtensile modulus of CFST laced columns are different has been taken into account,as a result, the calculation for the neutral axis and the moment of inertia is muchmore accurate. We get a more accurate and concise formula in the end. Finite element analysis for the joints performance and lateral performanceof CFST laced columns has been done in this article. It analysis the destructionprocess of the joints under tension and compression, and analysis thedisplacements of CFST laced columns under different horizontal force withdifferent arrangements of webs, and different number of columns limb. Finiteelement analysis results and the theoretical results are compared to verify theaccuracy of the theoretical formulas.