Evaluation of Tsai-Wu criterion and Hankinson's formula for a Brazilian wood species by comparison with experimental off-axis strength tests

This article presents a study based on the Tsai-Wu failure criterion as well as Hankinson's formula that evaluates the offaxis strength of wood. For materials such as wood, the strengths are a function of the grain orientation and also are different in compression and tension for the same direction. By considering this anisotropic behaviour, the failure criterion of the Tsai-Wu was adopted in this work. To establish this criterion, the strengths were determined from compressive and tensile tests as well as shear and biaxial compressive tests. In addition, off-axis uniaxial tests were performed, and the experimental results were compared with those obtained by the discussed criteria. In these tests, specimens of Goupia glabra-Brazilian wood species were used. This study's most important conclusion was: the predictive ability of the Tsai-Wu criterion was close to that of Hankinson's formula and fits the experimental results of the compressive and tensile tests well.