Analysis of Plan

[seaw]

What are advantage and disadvantage if I want to analyze plan (slab-beam-column) by grid or space structures and reduce the torsional stiffness of beam instead of manual transfer load from secondary beam to primary beam.
Thanks.

 

[StructuralDzine]

In a grid structure part of the load will often be carried by torsional moments. If you don't want to design beams for torsional loads you can reduce the torsional stiffness of members by a factor of say 100. This should make torsional moments negligible for design.
However you should then provide minimum torsional reinforcement to provide ductility to cover compatability torsion. Also the bending moments in the members will increase.
In some cases, e.g. a beam cranked in plan, torsion is necessary to carry the load and cannot be ignored.

Chris Rohde
Editor, Structural D-zine

http://www.topica.com/lists/Structuraldzine