Numerical Modeling and Experiments on the Role of Strand-to-Strand Interface Quality on the Properties of Oriented Strand Board

This paper discusses numerical modeling and experimental results on stress transfer in wood composites. The numerical model treats adhesive bonds using the concept of an imperfect interface. The displacement discontinuity at an imperfect interface is proportional to the tractions at the interface. A stiff interface will result in little discontinuity and maximum translation of wood component mechanical properties into bulk properties. If the interface allows slippage, however, the mechanical properties will suffer. The numerical modeling can calculate the mechanical properties of oriented strand board as a function of realistic strand undulation geometries and of the properties of the glue lines. To provide input to the numerical modeling, a new experimental method was developed to measure strand-to-strand interfacial properties as a function of the amount of glue. The modeling and experiments were done on unmodified strands and on densified strands.