Birch plywood sample tension and bending property investigation and validation in solid works environment

Abstract

Birch plywood has proved itself to be one of the most rational ways of wood processing. Growing demand of high performance birch plywood products requires a complex numerical analysis based on Finite Element Method (FEM), instead of using simple analytical assumptions, which prevent optimization of plywood construction (lay-up). In the research samples of birch plywood of several thicknesses, both sanded and non-sanded, with fiber direction of external veneer both in the longitudinal and transverse directions were tested. An extensometer and optical strain gauge were used for strain measurement. The FEM analysis, using commercial software SolidWorks Simulation Premium (SW), versus experimental bending and tension testing according to LVS EN 789 was carried out in this paper. The analysis of results indicates that there is a high correlation between the results of the experiments and the FEM. Particularly for in tension loaded specimens one can be tested up to the maximum ply strength (100 MPa); meanwhile, in bending up to 71MPa -the average stress in load bearing ply at the proportionality limit. Due to software restrictions, shear stresses cannot be evaluated. Future studies are considered to investigate terms for designing plywood with dynamic properties of strength and stiffness to be taken into account.