INFLUENCE OF VERTICAL DENSITY DISTRIBUTION ON BENDING MODULUS OF ELASTICITY OF WOOD COMPOSITE PANELS : A THEORETICAL CONSIDERATION

Vert~cal density distribution (VDD) has long been recognized as an important structural characleristic of wood composite panels. However. only a qualitative understanding of its influence on bo.ird properties has been achieved. This papcr reports a theoretical consideration of the influence of VI)D on bending modulus of elasticity (MOE:) of composites. The consideration was based on the construction of VDD with a trigononictric fi~nctron, linear layer MOE-layer dcnsity relationship, and laminate ~heory. Theoretical consideration shows that MOE henetits from the high density surface layer ; ~ n d increases lincarly with the increase o f peak tlensity, hut ~naximum MOE does not occur when peak density is right at the board surfacc. Ke\b~,ortl.s: Density, laminate theory. modulus of clasticity, wood composite panels, vertical dcnsity