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

Experimental Investigation of Cross Laminated Timber Elements with Holes or Notches at In-Plane Beam Loading Conditions

“…In the case of net shear stress in the transversal layers τ xy,net , which is relevant for shear failure mode II, the calculated values are much higher compared with the proposed characteristic and expected mean strength values in Section 2.4. However, the obtained values are consistent with previous tests on CLT beams, where high net shear stresses were also obtained without obvious failure in shear mode II; see [17,29,30]. These results indicate the strong conservative side of the proposed Equations ( 11) and (12).…”

“…where f v,tor is a torsional shear strength and f R is the rolling shear strength. A compilation of literature-based test results on individual crossing areas was presented in [16,17], indicating mean values of f v,tor,mean = 3.50 N/mm 2 and f R,mean = 1.50 N/mm 2 , where both strength components are seemingly size-independent with a constant ratio f v,tor /f R ≈ 2.25-2.5. A characteristic torsional shear strength of f v,tor,k = 2.50 MPa was proposed in [2] and a rolling shear strength of f R,k = 1.40 MPa for b/t ≥ 4 and f R,k = 0.80 MPa for b/t < 4 was proposed in [26].…”

“…However, the original model of Flaig and Blass [4,11], which was also used in the ongoing revision of EC5 [8] suffers from some drawbacks in terms of assumptions regarding the distributions of internal forces and shear stresses acting in the crossing areas, as pointed out in [12][13][14][15][16]. Recent 3D numerical-FE analyses, as presented by Jeleč et al [16,17] and Danielsson et al [18], indicate significant differences in the force and stress predictions in the crossing areas compared with the original model. Some alternative assumptions and model improvements aimed at a more accurate prediction of internal force and stress distribution were therefore presented by Danielsson and Serrano [15] and design proposals by Jeleč et al [16,17,19,20].…”

“…Recent 3D numerical-FE analyses, as presented by Jeleč et al [16,17] and Danielsson et al [18], indicate significant differences in the force and stress predictions in the crossing areas compared with the original model. Some alternative assumptions and model improvements aimed at a more accurate prediction of internal force and stress distribution were therefore presented by Danielsson and Serrano [15] and design proposals by Jeleč et al [16,17,19,20]. However, these improved models and design proposals have not yet been adapted to consider holes or notches in CLT beam elements.…”

Strength Properties of Structural Glulam Manufactured from Pine (Pinus sylvestris L.) Side Boards

“…Literature on the subject concerning such elements from bonded wood is scarce. A certain analogy to such structures may be found in bent elements manufactured from wood-based materials with the vertical arrangement of layers, such as laminated veneer lumber (LVL), with or without reinforcement [ 27 , 28 , 29 ], elements manufactured from cross laminated timber (CLT) [ 30 , 31 ], which in various structures are applied both flat and edgewise, as well as all types of I-beams, in which the web is found in the plane of loading [ 32 ]. Numerous studies present research results for such structures.…”