Laterally Loaded Timber Columns

A general theoretical expression for the load-carrying capacity of timber beams, taking into account lateral instability, and columns, has been developed under the assumption that the conditions are elastic until failure but that the structures have initial curvature and torsion. The general expression is specialized for plane bending (axially loaded columns and combined axial force and moment) and pure bending taking lateral instability into account. Tests carried out in Denmark and Holland for axially loaded columns are referred to, and a series of tests carried out with laterally loaded columns is described. The correspondence between theory and test results is very satisfactory when the measured material values, etc. are used for each test specimen. In a number of graphs it is shown how the load-carrying capacity for columns (axially and centrally loaded) and for beams without axial force is dependent on the various parameters. It is shown to be possible to disregard the influence of certain factors, among others the initial torsion.