| Imitated ancient buildings set in modern science and technology and the history and culture, with distinctive ethnic features and regional culture, are widely used in many historic city. As a special part of imitated ancient building, the mechanical properties of eave column joints with Dougong are different from joints of ancient buildings and modern conventional buildings. Currently, for eave column joints with Dougong in imitated ancient building is lack of experimental research and theoretical analysis.Four specimens of steel eave column joints with Dougong in 1/1.5 scale were tested under low-cyclic reversed loading in order to investigate the effect of the slenderness ratio and the axial compression ratio of square steel tubular columns on the seismic performance of eave column joints with Dougong in imitated ancient building.The hysteretic performance, degradations of rigidity and strength, ductility and dissipation capacity were obtained. The failure modes and strain distribution in joint area were analyzed. The results indicate that the failure of eave column joints with Dougong is mainly caused by weld fracture of Ludou and the connection between bottom flanges and webs of the square steel tubular columns, plate fracture of the heat affect zone between bottom flanges and horizontal stiffening ring of the columns. The hysteretic loops of the column joints are plump. The deformations of Ludou and the bottom of the square steel tubular columns were full in joint area. The column joints had insignificant degradations of rigidity and strength. As the joints failed, the ductility factor of the story drift and the equivalent viscous damping coefficient were both high which show the good deformation capacity and dissipation capacity of the joints.Finite element software ABAQUS was used to carry out the numerical simulation analysis, and the calculated results are basically consistent with the experimental results.On this basis, the parametric analysis of eave column joints with Dougong in imitated ancient building was observed. In order to study the further research of seismic performance of eave column joints with Dougong, the axial compression ratio and the slenderness ratio of square steel tubular columns and width-thickness ratio of Ludou were analyzed as parametric analysis, influence regularity of loading capacity, rigidity and stress distribution were obtained. It is shown that the bearing capacity and rigidity of the column joints ascends firstly and then descends as the increasing of the axial compression ratio within a certain range. The bigger slenderness ratio of square steel tubular column is, the smaller bearing capacity and rigidity of the column joints is.When the width-thickness ratio of Ludou is beteween 50 to 65, the growing rate of bearing capacity and rigidity of the column joints gets faster as the increasing of the width-thickness ratio of Ludou.The research results will provide reference for the seismic design and practical application of eave column joints with Dougong in imitated ancient buildings, and be helpful for the further research on eave column joints with Dougong. |
