Perpendicular to grain and shear mechanical properties of veneer-based elements glued from single veneer sheets recovered from three species of juvenile subtropical hardwood plantation logs

Abstract

This paper quantifies the mechanical properties perpendicular to the grain and in shear of glued rotary peeled veneers, as would be encountered in veneer-based structural products (i.e. by including both the effects of hot pressing the veneers and the glue used during the manufacturing process), of three species recovered from juvenile (early to mid-rotation) subtropical hardwood plantation logs. This underutilised resource has currently little to no commercial value in Australia but proven potential to produce attractive veneer-based structural products. Determining these unknown properties is important as they constitute essential input data to ultimately predict the behaviour and design properties of veneer-based structural products in cost-effective numerical simulations. Two species planted for solid timber end-products (Gympie messmate-Eucalyptus cloeziana and spotted gum-Corymbia citriodora) and one species traditionally grown for pulpwood (southern blue gum-Eucalyptus globulus) are considered in the paper. The dynamic Modulus of Elasticity, compressive and tensile strengths perpendicular to the grain of veneer-based elements, each manufactured from single veneer sheets, were experimentally measured and are analysed herein. These properties are found to have no to weak correlation to the parent veneer sheet dynamic Modulus of Elasticity parallel to the grain, a value which is commonly measured in line to grade veneers. The Shear Modulus (in the longitudinal-tangential plane), also referred to as "Modulus of Rigidity", through-the-thickness and rolling shear strengths were also experimentally measured and the results are discussed in the paper. Little to no correlation to the veneer sheet dynamic Modulus of Elasticity parallel to the grain is also found for these properties. Weibull distributions are fitted to all test results and presented to probabilistically consider the investigated properties in numerical simulations of veneer-based structural products.

Veneer-based timber circular hollow section beams: Behaviour, modelling and design

“…Other properties were taken from the literature, either for Gympie messmate (when available) or for hardwood species of similar density. Specifically, the MOE in the radial ER and tangential ET directions, and the shear modulus in the longitudinal-radial GLR and longitudinal-tangential GLT planes were taken as the typical values encountered for juvenile Gympie messmate [28]. Note that these values were shown to be uncorrelated to EL [28] and were herein assumed as constants.…”

“…Specifically, the MOE in the radial ER and tangential ET directions, and the shear modulus in the longitudinal-radial GLR and longitudinal-tangential GLT planes were taken as the typical values encountered for juvenile Gympie messmate [28]. Note that these values were shown to be uncorrelated to EL [28] and were herein assumed as constants. The shear modulus in the radial-tangential GRT plane and the Poisson ratios γLR, γLT, γRT were taken for species of similar density in [29].…”

“…The rolling shear strength fs,RT was taken as the 50 th percentile value measured in [28] on the same resources used in manufacturing the CHS. Table 4 summarises all tensile and shear strength values used.…”

Splitting capacity of Eucalyptus globulus beams loaded perpendicular to the grain by connections

“…In this regard, Eucalyptus globulus Labill (also known as southern blue gum) stands out as a highperformance hardwood of significant interest, due to its fast growth, high mechanical properties, and good natural durability. Recently, there has been increasing industrial and institutional interest driving scientific research on E. globulus in different fields, such as silviculture [5][6][7][8], mechanical characterisation of the material with small clear specimens [9,10] and structural size [11,12], performance of bonded joints for laminated products [13,14], as well as research related to the development of higher added value building and engineering wood products using this species, such as finger-jointed solid timber [11], glued laminated timber [15], cross-laminated timber (CLT) [16,17], laminated veneer lumber (LVL) and plywood [18][19][20] or nail-laminated timber (NLT) and NLTconcrete composite floor panels [21].…”

A comparative study on the mechanical properties of laminated veneer lumber (LVL) produced from blending various wood veneers

“…), which was devised for solid timber specimens. The procedure has been previously applied to LVL samples and proven successful(Ardalany et al 2011;Gilbert et al 2018). The sample dimensions are shown in Fig.a.…”