The stress-displacement relation of wood perpendicular to the grain

Summary A method for measuring the complete stress-displacement relation in both tension and shear and some experimental results on Nordic redwood (Pinus sylvestris) are presented. The complete stress-displacement relation also includes the post-peak behaviour, i.e. the descending branch of the curve. The influence of annual ring orientation and moisture content on the form of the stress-displacement curve for the fracture process zone has been examined, and the results show that the normalised curve in tension is independent of annual ring orientation and moisture content.