Discussion of the failure criterion for combined bending and compression

One of the conclusions of the stability group of CIB-Wl8A was that the Code must allow for analytical solutions for stability design based on quasi linear behaviour and must rever to these methods (p.e. to the Larsen-Theilgaard method for columns). Although a new parabolic failure criterion for bending with compression is proposed for the Eurocode, based on glulam simulation, the interaction equation for in plane buckling of the code, being applicable for short columns as well, suggests a much less curved failure criterion. It therefore could be seen as a task of the stability group to reconsider the failure criterion. For that purpose a derivation is given of a consistent simple improved failure crite­rion for bending with compression, that may account for the influence of quality and moisture content, leads to simple interaction equations for beam-columns and may meet the requirements of the Eurocode. Together with the proposal of CIB-paper 23-15-2 a possible consistent design method for braced and free beam-columns is proposed for the Eurocode and is used in the new Dutch Code. In the appendix an explanation is given of the bearing- and shear strength.Bio-based Structures & Material