Analysis of structural materials interaction of composite plywood by finite element method

This study deals with the investigation of changes of the relevant plywood mechanical properties, under static load, depending on the influence of glass fibres. Using different species of wood (beech and poplar), with respect to their mechanical properties, attempts were made to optimise the system: wood - glass fibre - adhesive. The values of shear stress and strain in the ply of adhesive (glueline) were taken as the basic optimisation criterion. The differences between stress values caused by bonding homogenous and heterogeneous materials were also analysed, i.e. veneer with veneer, and veneer with glass fibre. For better understanding of inherent stress in the ply of adhesive, the stress in veneer and composite plies was analysed, too. The results of the analysis, based on the finite element method, indicated that the stress in the ply of adhesive was lower in reinforced plywood than in control plywood. Minimum stress value was recorded in the combination of beech veneer and glass fibres, and maximum value of stress decrease was recorded in the combination of poplar veneer and glass fibres. Similar properties of stress distribution are present in plies of beech and poplar veneer due to glass fibre reinforcement. The results of experimental analysis of shear strength in the ply of adhesive were in accordance with the results obtained by the finite element method.