Measurement of the shear properties of clear wood by the Arcan test

In this work, the identification of the shear properties of maritime pine ( Pinus pinaster Ait.) wood was investigated by applying the Arcan test method. For this purpose, an ad hoc Arcan fixture was designed for which clear wood samples could be tested along all the material planes of symmetry - LR, LT and RT planes. For the accurate evaluation of the shear moduli, correction factors taking into account the non-uniformity of the shear stress and the shear strain distributions at the gauge section were determined with finite element analyses. Experimentally, two 0/90 rosettes were glued on both frontal and back surfaces of the specimens in order to take into account any through-to-thickness shear strain variation. It was found that the Arcan test is suitable for the identification of the shear moduli of wood in all its natural planes. The failure of the Arcan specimens systematically occurred under a concentrated stress state nearby the V-notches. Nevertheless, it was shown that an accurate estimation of the shear strengths of wood can be achieved by the Arcan test.