Planar shear moduli of rigidity of an oriented strand board from bending and shear tests

Abstract

The planar shear modulus of rigidity has been recently utilised in the structural grading of oriented strand board (OSB). However, data on the planar shear moduli of rigidity of oriented strand board are sparse. This has been attributed to the nature of existing tests for determination of planar shear properties, which are deemed to be complex and expensive. The planar shear moduli of rigidity of an 18-mm thick oriented strand board have been determined from bending test and the planar shear test in European Standard EN 789. The ratio of the average planar shear modulus of rigidity in the major axis from the shear test to the average planar shear modulus of rigidity in the major axis from the bending test is 1.17. The corresponding ratio of the average planar shear moduli of rigidity in the minor axis is 1.13. The close comparison of the stiffnesses obtained from the shear and bending tests suggests that a bending test is a likely viable alternative to the shear test for determination of the planar shear stiffness. However, comparative tests of other types and thicknesses of OSB are required in order to establish the levels of bias in the planar shear stiffnesses obtained from the bending test.