Numerical Study on the Strength of Pipe Joints

Abstract EN

With respect to the collapse behavior of joints in a steel pipe truss structure, in the present study, we carry out numerical analyses using a general-purpose FEM software package on the yield strength and the stress distribution near the connection in order to obtain information on the collapse behavior and the yield strength of joints.

T-joint and Y-joint are investigated.

It is found that the joint strength is proportional to the λth power of thickness T of a main tube for various joints with a fixed branch-to-chord diameter ratio d/D.

The index λ changes with d/D and in the range of d/D=0.1 to 0.91, λ≅1.93 to 1.55 holds with smaller values corresponding to larger d/D.

A compressive axial force along the main tube will reduce the joint strength, and it is also found that the strength-reduction ratio for Y-joint is almost the same as that for T-joint having the same T and d/D.

Also, the joint strength is influenced by the span length of the main tube.

The joint strength decreases as the span length increases.

However, the influence is small for small d/D.