Effects of Shear Coupling on Shear Properties of Wood

Under pure shear loading, an off-axis element of orthotropic material such as pure wood undergoes both shear and normal deformations. The ratio of the shear strain to a normal strain is defined as the shear coupling coefficient associated with the direction of the normal strain. The effects of shear coupling on shear properties of wood as predicted by the orthotropic elasticity theory were validated using our recently developed shear test fixture. The validation also serves to demonstrate that the shear test fixture possesses the capability to introduce a state of pure shear to the critical section of a specimen as required and that orthotropic elasticity theory should be used to describe the mechanical properties of pure wood