Evaluating the viscoelastic shear properties of clear wood via off-axis compression testing and digital-image correlation

Abstract Highly anisotropic materials like wood and unidirectional polymer composite structures are sensitive to shear deformations, in particular close fixed joints. Large wooden buildings and, e.g. wind-turbine blades, designed last for decades, hence susceptible unwanted creep deformations. For improved structural design, the shear-creep properties of material needed. These rarely available literature, possibly because technical difficulties achieve a well-defined shear-stress state test specimens. cost-efficient testing, this goal pure stress necessarily needs be compromised. In present study, we propose simple method based on uniaxial compression cubes, but is equally applicable fibre composites. The viscoelastic Norway spruce (Picea abies) under off-axis tests have been characterised all three directions. performed controlled climate chamber strains captured using digital-image correlation.