Truss chords buckling

Resumo

The present work proposes reducing coefficients on the buckling length of trusses chords when the
normal acting on these chords is not constant throughout the chord. The normal maximum is considered acting
on the entire compressed part of the chord, but with a reduced buckling length. In this text, it is obtained an
equivalent normal, which, constant in the chord, generates the same deformation energy as the acting variable
normal. This equivalent normal has a value lower than the maximum acting normal. It is made, then, the

proportion to obtain the reduced buckling length to consider. It is solved, step by step, the case of the double-
supported truss under point load in the middle of the span and shown the results for the double-supported truss

under uniformly distributed load and the two-span continuous truss, also under uniformly distributed load. The
solution of the differential equation with the variable normal in the chord, exact, of difficult solution, is also
showed to notice the validity of doing the procedure via energy, approximate. An illustrative numerical example
of the application of these buckling length reduction coefficients is shown to easy the practice.