In previous versions of the program, the automatic calculation of the susceptibility to local buckling due to compression was already included assuming that each of the flat elements making up the section buckled in an isolated manner (independent from the rest), and the possibility was included, for any other type of buckling other than the individual type to be considered, to modify the local buckling coefficient which affects the slenderness parameter associated to each element. In this new version, the automatic calculation of the susceptibility to local buckling due to compression considering the possibility that several elements can buckle together as if they were a single element, is also included, hence combined buckling modes are obtained. The program is able to detect and analyse the buckling in a group of elements in the following cases:
- Element sequence with all their ends aligned along a straight line
- Element sequence with all their ends arranged along a circumference arc with small curvature
- Element sequence making up a cell
The combined buckling is also studied if the elements making up the section have been stiffened, which is commonly referred to as buckling due to distortion. Regarding the stiffened elements, a new assistant has been implemented for the design with standard reinforcement in accordance with that exposed in EC9.
