Flexural buckling of beech LVL columns : experimental report

Abstract

Glulam made of beech laminated veneer lumber GL75 is increasingly used in timber construction due to its high strength, stiffness and availability. Especially for columns of multi-storey timber buildings and highrise buildings or trusses. For such members in compression, the flexural buckling verification is typically decisive. However, the available design methods in EN 1995-1-1 were derived for softwood columns.

The aim of the tests was therefore to experimentally determine the buckling curve of beech LVL columns. The load-displacement behaviour, load-bearing behaviour and failure behaviour of the columns were investigated. In this way, relevant parameters influencing the load-bearing capacity of flexural buckling and the differences compared to the behaviour of columns made of softwood could be worked out. The experimental results were compared with the design procedures according to EN 1995-1-1. Finally, the experimental results were used to validate an FE model for further parameter studies.

Based on the numerical and experimental investigations, design recommendations for the kc-method for flexural buckling for beech LVL GL75 columns were developed in the form of a modified βc coefficient.