Abstract： Several groups of XKK joints with different geometric characteristics were analyzed. The influence of geometric parameters on the ultimate strength was investigated and explained graphically. The elastoplastic finite element analysis (FEA) was performed for the circular tubular XKK-Joints to demonstrate the strength capacity, plastic development zone, destruction forms, and stressstrain distribution status of the connections. The results indicate that the bearing capacity of XKK joints can be improved by the increasing of the diameter ratio of branch to chord or the diameter ratio of another branch to chord. The angles of branch-chord and branch-branch have slight influence on bearing capacity. The ratio of diameter to thickness should be controlled within 15 to 20 with the axial compressive force coefficient of chordtube less than 0.6. The destruction forms of spatial penetrated joints are closely related to the geometric characteristics with good plastic deformation capacity.
2011, Vol. 32 
