Bearing capacity analysis on multi-dimensional CHS joints with tree form in large span structure

Based on ADINA, nonlinear analysis with monotonic and hysteretic loading modes was applied to research the failure modes and bearing capacity of multi-dimensional CHS joints with different construction parameters in tree pipe structure. In non-linear Full Newton-Raphson algorithm, low speed dynamic damping factor was adopted to restrain the sub-dynamic effect to implement the whole process of quasi-transient tracking stable failure. The implicit failure modes and ultimate bearing capacity were obtained with four types which are non-strengthen ribbed, local stiffness respectively in the column of the connection region and the column and branch chords around the connection. The results indicated that the strengthen points in the column and chords could effectively improve the failure modes, ductility, mechanical technology and economy.