MODELING THE ELASTIC PROPERTIES OF SOFTWOOD - PART I - THE CELL-WALL LAMELLAE

A procedure for determining the nine equivalent orthotropic elastic co nstants for a cell-wall lamella is presented. A two-stage analytic hom ogenization method is proposed. It is shown to give results which are similar to those obtained from a full numerical finite element solutio n for an idealised representative volume element. The method, which ca n accommodate arbitrary proportions of cell wall constituents, is used to determine the equivalent,elastic constants for lamellae in the sec ondary cell wall layers and the compound middle lamella of a typical s oftwood tracheid at a nominal 12% moisture content.