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Most engineered wood components and their performance are dependent on the use of adhesives. To be able to conduct simulations, a general understanding about their mechanical behaviour under different load cases and environmental conditions is needed. Especially the temperature-dependent elasticity is of great importance for future applications as automotive components. Therefore, the tensile modulus of four common polymer-based wood adhesives (i.e., one-component polyurethane, two-component polyurethane, epoxy-silan and phenol–resorcinol–formaldehyde) at varying temperatures of −30°C, +20°C and +80°C were investigated. The aim of this study was to give fundamental insight into the elasto-mechanical behaviour of common wood adhesives. The experimental investigation showed a significant influence of the temperature on the tensile modulus. The highest tensile moduli were observed for all tested adhesives at −30°C with a significant decrease with increasing temperature. Results of previous investigations confirmed this high-temperature dependency of the polymers. [ABSTRACT FROM AUTHOR]

EN 302-1 and EN 205 are among the most commonly used standards for the approval as well as research of wood adhesives to evaluate bond strength. The present study investigates the sensitivity of the lap-joint samples to a possible error in groove cutting as well as the influence of using steam-treated and untreated beech wood on tensile shear strength. The lap-joint specimens cut with 0.5 mm too shallow and 0.5 mm too deep grooves was compared with samples cut precisely within the tolerances mentioned in the standards. A comparison of tensile shear strength between the joints manufactured out of steam-treated and untreated beechwood has been made. The results show a significant influence of groove depth on the resulting tensile shear strength. While deep groves (+0.5 mm) underestimate, shallow grooves (−0.5 mm) overestimate it dramatically. Additionally, the joints with steam-treated beech wood delivered lower tensile shear strength than those of untreated beech wood bonds when there is a considerable wood failure percentage. When the ultimate tensile shear strength of the adhesive bond approaches the shear strength parallel to the grain of wood, the impact of steam-treated beech wood on the estimation of adhesive bond strength is higher. [ABSTRACT FROM AUTHOR]