The effect of flexural–torsional buckling on the stability of timber members: a case study

Abstract

This study investigates the stability of timber members subjected to simultaneously acting axial compression and bending moment, with possible risk for torsional and flexural–torsional buckling. This situation can occur in laterally supported members where one side of the member is braced but the other side is unbraced. In this case, the free side will buckle out of plane while the braced side will be prevented from torsional and flexural–torsional buckling. This problem can be evident for long members in timber-frame structures, which are subjected to high axial compression combined with bending moments in which the member is not sufficiently braced at both sides. This study is based on the design requirement stated in Eurocode 5. Solution methods discussed in this paper can be of interest within the framework of structural and building Engineering practices and education in which the stability of structural elements is investigated. Article Highlights This case study investigates some design situations where the timber member is not sufficiently braced. In this case, a stability problem associated with combined torsional buckling and flexural buckling can arise. The study shows that the torsional and/or flexural–torsional buckling of timber members can be important to control in order to fulfil the criteria of the stability of the member according to Eurocode 5 and help the structural engineer to achieve safer designs. The study investigates also a simplified solution to check the effect of flexural torsional buckling of laterally braced timber members.

Non-linear analysis of the flexural-torsional stability of slender tropical glulam beams

“…In modern timber-frame structures, instability of structural members such as slender beams are one of the most important problems that structural engineers and designers must address. 1 Among the main instability modes of such structures, we may mention flexural-torsional buckling phenomenon also known as lateral buckling. In this phenomenon, the flexural buckling is coupled with the torsional buckling.…”

“…However, the effects of torsional and flexural–torsional buckling were not investigated especially on tropical wood-based structures. Hassan 1 investigated the stability of timber members subjected to simultaneously acting axial compression and bending moment, with a possible risk of torsional and flexural–torsional buckling. He found that the flexural–torsional buckling mode of the member should be checked to ensure that the lateral supports and bracing system are sufficient to withstand the flexural–torsional buckling of the unbraced part of the member.…”