Experimental and numerical investigations of cross-laminated timber elements at in-plane beam loading conditions

摘要

Cross laminated timber (CLT) at in-plane beam loading conditions presents a complex stress state wherefore several failure modes and geometry parameters need to be considered in design. The work presented here includes experimental investigations of CLT beams for comparison and validation of an analytical model and design proposals previously suggested by the authors. All relevant failure modes are considered; bending failure and shear failure modes I, II and III. The main focus is, however, on shear failure mode III relating to shear failure in the crossing areas between orthogonally bonded longitudinal and transversal lamination. The analytical model presented is an improvement of the analytical model which has been suggested to be used as the basis for design equations for the next version of Eurocode 5. The two design proposals presented are based on that improved analytical model. Experimental results show good agreement with the improved model and both design proposals. In order to study the influence of different lamination placements and varying lamination widths, comparisons between the improved analytical model and FE-analyses regarding magnitude and distribution of internal forces are presented and good agreement is obtained. Experimental and analytical results indicate only a small influence of reduced lamination widths close to the beam edges. This is a finding which is of practical interest since CLT beams in general are cut from larger elements, with no consideration of the location of the individual laminations with respect to the edges of the beam. (C) 2019 Elsevier Ltd. All rights reserved.