Structural performance of wood based sandwich panels in four point bending

Abstract

Current paper describes design, prototyping and experimental tests of wood based sandwich panels with plywood surfaces. In the first case 3D core of the sandwich panel is formed by thermoplastic glass fibre / polypropylene (GF/PP) composite and bonded to plywood in one manufacturing step. Other sandwich panel type consists of plywood skins and stiffeners with additional foam core filler made of environmentally friendly PU foam. Both types of sandwich panels are intended for applications in lightweight fast transformable housing applications. Experimental flexural tests demonstrates that wood based structures are competitive alternative for solid wood based plate materials. Average flexural modulus for sandwich panels with stiffener/foam core is 6.2 GPa and flexural strength 26.1 MPa at density of 325 kg/m3. Thermoplastic composite core allows to reach flexural modulus of 4.18 GPa and strength of 22.6 MPa at the same time maintaining low density magnitude at 235 kg/m3. It has been demonstrated that numerical analysis could be applied as a benchmark tool to evaluate mechanical performance of the panels comparing to idealized design.