Transverse Isotropy Modeling of 3‐D Glulam Timber Beams

Shear Moduli of Structural Composites from Torsion Tests

“…Lekhnitskii [8] applied St. Venant's formulation for torsion to orthotropic materials and obtained solutions for circular and rectangular bars with three mutually perpendicular planes of material symmetry. Davalos et al [9] applied this approach to orthotropic wood samples and presented a combined analytical/experimental method to obtain principal shear moduli. Lekhnitskii's solution can be successfully used for orthotropic samples; for more complex materials, Whitney [13] presented a solution incorporating transverse shear deformation for the torsion of rectangular laminated anisotropic composite plates.…”

“…A better approach is to pair samples with either the same or different cross-sectional dimensions but with material orientations normal to each other. Davalos et al [9] used this approach for paired orthotropic wood samples manufactured with the same crosssectional dimensions, but with principal material orientations perpendicular to one another. The corresponding two distinct equations were then solved by a method of successive substitutions.…”

“…The corresponding two distinct equations were then solved by a method of successive substitutions. In this study, we modify the approach proposed by Davalos et al [9] to obtain a more efficient solution by the bisection method [25,26]. Pultruded FRP structural laminates are considered, and to obtain samples of variable widths in the xz-plane, the pultruded laminates [Figure 3(a)] were bonded flat-wise, and vertical strips were cut from the bonded assemblies as shown in Figure 3…”

“…The torsion tests make use of either cylindrical rods [2,5] or rectangular samples [6], while the Iosipescu shear test [3] uses a flat specimen with side notches, similar to the sample proposed by Arcan et al [7], to develop a state of uniform stress in the gauge section. The computational procedure of shear moduli from torsion tests and linear elastic torsion theory for anisotropic bars [8] is well established [9]. Similarly, the Iosipescu test method has been extensively discussed by various researchers [6,10,11].…”

Evaluating Timoshenko Method for Analyzing CLT under Out-of-Plane Loading

“…These constants are three elastic moduli, three Poisson's ratios, and three shear moduli. Orthotropic material property for timber can be reduced to transversely isotropic material by considering the radial-tangential plane to be isotropic, as the material properties are reported to be of the same order [30]. This assumption means that elastic moduli (E R and E T ) and Poisson's ratio (ν RT and ν TR ) normal to each other in the radial-tangential plane becomes equal.…”