Experimental and numerical column buckling analysis of hardwood Cross Laminate Timber (CLT) panels

Abstract

This paper investigates the column buckling behaviour of three-layer Cross Laminated Timber (CLT) panels under compression, from both the experimental and numerical point of view. The main aim of present study is hence to define the expected load-bearing capacity for these composite CLT solutions, and to assess the typical fracture mechanism for two different series of specimens of possible technical interest for construction applications. To this aim, a total of 14 column buckling experiments is carried out. First, a set of 7 homogeneous speciemens (“HO” series), which are entirely made of beech, are investigated. Their load-bearing capacity is compared with the column buckling performance of 7 hybrid specimens (“HB” series), whose inner layers are made of Corsican pine. Overall, the experimental analysis gives evidence of a rather stable column buckling capacity for CLT panels, with evidence of major failure mode due to out-of-plane bending phenomenam, but also rolling shear and delamination. Finally, further assessment of experimental evidences is provided by extended analytical calculations (based on existing formulations, including the Eurocode 5 approach) and even Finite Element (FE) numerical analyses for the examined three-layer CLT compositions. Comparative results are discussed in terms of structural performance, capacity, weakness of analytical models for CLT solutions.