structural bracing types

huangyhg

structural bracing types
re: structural bracing for lateral loads:
what is "discreet bracing"?
what is "relative bracing"?
when would each be applied to a structure?
where would each be applied?
how would each be applied?
thank you for your time ...
discrete bracing (as opposed to continuous bracing) is referred mainly when attempting to prevent the lateral torsional buckling of a beam or flexo torsional buckling  of a beamcolum and the bracing restraint is provided only every some distance along the member length.
for example, if the top flange of a simply supported beam in a roof has only effective lateral restraint at ends, quarters and midpoint, these elements of bracing provide discrete bracing against lateral torsional buckling at the named points. were the top flange embedded in some slab, it would have continuous bracing against ltb coming from the same.
in relative bracing you brace one member or part of it typically against a parallel one.
for example, you may join the top flanges of two parallel girders in a bridge to form a triangulated structure in the horizontal plane in such a way that the likelihood on lateral torsional buckling of any of the top flanges of the beams comes greatly restricted by the far bigger stiffness of the so formed secondary bracing structure. hence relative bracing can be an effective way to brace, and some times the more convenient.