Advancement in prediction of shear strength and stiffness of cross laminated timber beams

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

“…The model reviewed in Section 2 is also based on a 1D-FE analysis, which is quite a simplification compared with the real condition including the geometric and material heterogeneity of the CLT elements. This is particularly evident in test series N2, where the shear failure in the crossing areas also occurred on the non-notched side of the beam, but not in the lowermost crossing area as expected according to the original model [6,11], but in the crossing area near the centre line of the beam according to the improved model [16,17,20]; see Figure 13. The stress distribution in the beam width direction is even more pronounced for prismatic CLT 5s and CLT 7s elements and must be considered accordingly.…”

“…However, it should be noted that several simplifications and assumptions were implemented into the model discussed in Section 2 and that it is closely related to the original analytical model for prismatic beams presented in [6,11]. Several previous studies [16][17][18][19][20] indicate that the assumed stress distributions in the beam height and beam width directions according to the original model do not agree with the results of 3D-FE, as mentioned in the introduction. The model reviewed in Section 2 is also based on a 1D-FE analysis, which is quite a simplification compared with the real condition including the geometric and material heterogeneity of the CLT elements.…”

“…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.…”

Performance study on mounting system for displacement transducer in mechanical tests of timber samples using photogrammetry method

“…Some most commonly used test methods are specified in the current European Standard BS EN 408:2012(BSI 2012 or purposedeveloped by researchers for various applications. LVDT is one of the most commonly used instrumentations for calibrating the materials' mechanical properties, such as compression tests (Faggiano et al 2011, Aicher andStapf 2016), picture frame or diaphragm tests for in-plane shear modulus (Brandner et al 2017, Turesson et al 2020, shear field tests for cross-laminated timber beams (Jeleč et al 2021), etc. In contrast to some of the other tests at the structural element level such as the four-point bending test (Zhang et al 2021), seismic performance test for timberframe shear walls (White et al 2009), etc., in which the LVDTs are usually measuring a much larger displacement, the LVDTs used in the calibration of materials' mechanical properties are normally expected to capture a much smaller displacement, thus a small error may lead to significant distortion of the measuring properties.…”

Performance study on mounting system for displacement transducer in mechanical tests of timber samples using photogrammetry method

“…Some most commonly used test methods are specified in the current European Standard BS EN 408:2012(BSI 2012 or purpose-developed by researchers for various applications. LVDT is one of the most commonly used instrumentations for calibrating the materials' mechanical properties, such as compression tests (Faggiano, Grippa et al 2011, Aicher andStapf 2016), picture frame or diaphragm tests for in-plane shear modulus (Brandner, Dietsch et al 2017, Turesson, Berg et al 2020, shear field tests for cross-laminated timber beams (Jeleč, Dokšanović et al 2021), etc. In contrast to some of the other tests at the structural element level such as the four-point bending test (Zhang, Gharavi et al 2021), seismic performance test for timber-frame shear walls (White, Miller et al 2009), etc, in which the LVDTs are usually measuring a much larger displacement, the LVDTs used in the calibration of materials' mechanical properties are normally expected to capture a much smaller displacement, thus a small error may lead to significant distortion of the measuring properties.…”