ABSTRACT
The aim of this paper is to provide data on the use of thin-walled members in seismic resistant structures. The ductility of thin-walled sections in the plastic area is studied by evaluating the plastic moment, the ultimate moment, the post-critical behaviour and the rotation capacity of thin-walled members. The evaluation of the rigid-plastic curve shape of the plate is an important step for estimating the ductility of thin-walled members. This curve was theoretically determined and validated by experimental results. For a rapid determination of the ultimate rotation and the ductility of thin-walled members, a computer program named DUCTROT TWM has been elaborated. In the paper the behaviour factor q is determined for built-up beams formed by two channels or lipped channels.
