Determination of The Effects of Fiber-Reinforced Polymer Types on the Screw Withdrawal Strength of Wood Based Sandwich Panels

Sandwich panels are favorable materials for structural or non-structural components due to durability, lightness, and longevity in service life. The strength of a structural system often depends on the interconnections between the components of the structure. Screws are one of the most widely used fasteners in construction. In this study, the screw withdrawal strength of wood based sandwich panels reinforced with jute fabric, glass fiber reinforced polymers (GFRP), and plaster mesh (PSM) via polyurethane adhesive (PUR-D4) was investigated. In predicting the screw withdrawal resistance, withdrawal load capacity, density, and withdrawal stiffness of the wood based materials and fabric jute, GFRP, and PSM in each layer, were considered. Moreover, the screw withdrawal strength of the panels was examined. Screw withdrawal tests of panels were conducted according to TS EN 13446 standard. The highest screw withdrawal strength was obtained for the based sandwich panels reinforced with GFRP (9.31 N/mm2). Furthermore, the difference between experimental and predicted screw withdrawal resistance changed from 4% to 9%. Besides, the highest air-dry density was obtained for the based sandwich panels reinforced with GFRP (0.620 g/cm3). Furthermore, the difference between experimental and predicted screw withdrawal resistance changed from 1.2% to 2%. In addition, the wood based sandwich panels reinforced with GFRP had a considerable increase in the screw withdrawal strength compared with the unreinforced, fabric jute, and PSM reinforced samples.