Lattice girders with I-sections and slotted gusset plates - Tests and simulations for overall behaviour and compression member capacity

Nowadays trusses are often designed with I-sections only and no direct connection between the diagonal members and the chords. For the truss joints gusset plates—welded to the chords—are used, which are slotted for the welding connection to the diagonal member.

The main focus in this paper is the specific stability behaviour of such diagonal members in compression, leading to an interaction behaviour of member buckling out of plane and local buckling of the gusset plates.

The results of four full scale tests on a lattice girder are presented in detail. The compression member capacity of the tests is compared with the results of a FE-model, considering the measured geometric imperfections.

In addition also the overall load carrying behaviour of the truss in the test is analysed and compared with simplified models for global analyses, both for the load—deformation behaviour and for the relationship between load and member axial force.