Q: ETABS always design beams for torsion. Is it possible to avoid design for torsion? I also use another software which offers this facility. Can’t we have it in ETABS too?
A: This logic is incorrect even if it is available in other software. Either you have the force in a component and design for that or you don’t have it and ignore it. In most building systems torsion in beam develops due to compatibility of deformations. This can be handled conveniently by reducing the torsional stiffness of beam as in most beams torsional stiffness is much smaller than that given by torsional stiffness formula. However we don’t believe that a shortcut to avoid design for torsion should be given in ETABS as this will be misused and often the errors it would cause would be un-conservative. So to reduce torsional moment in beams best remedy is to reduce its torsional stiffness. It must be kept in mind that torsion which develops due to equilibrium requirements must be included in design.