Numerical simulation analyses of single lap joints for wood-PE composites formed with epoxy and acrylic ester adhesives

Abstract

Wood powder/polyethylene composites (WP/PE) were surface treated by plasma discharge and bonded with epoxy resin and acrylic ester adhesives, respectively. The finite element model of the single lap bonded joints of WP/PE was established through the elastic-plastic finite element method, and the influences of adhesive and lap length on the stress distribution in the adhesive joints were analyzed. The results showed that polar oxygen-containing groups were introduced to the WP/PE surface with the plasma treatment, which improved the bonding properties. The peak values of Mises equivalent stress, peel stress, and shear stress of the bonded joints were mainly concentrated at the end of the bond joint. The peak values of the stress in the lap zone of the high-modulus epoxy resin-bonded joints were higher than those of the low-modulus acrylic ester-bonded joints. With an increased length of the joints, the Mises equivalent stress peak value at the end increased slightly, the peeling stress peak value decreased slightly, and the shear stress peak value changed little. The elastic modulus of the adhesive had a great influence on the stress distribution, and the change in the lap length was not remarkable enough to improve the stress distribution of the adhesive joint.