An alternative way of determining mechanical properties of wood by means of cutting forces

The cutting force is an energetic effect of splitting material, and might be therefore considered from a point of view of modern fracture mechanics. The dedicated mathematical model developed for description of the wood cutting has been developed here on the base of fracture theory and includes work of separation (fracture toughness) in addition to the material plasticity and friction. The effect of the cutting edge dullness is considered in the model by taking into account the cutting edge radius. Moreover, forecasting of the shear plane angle by the numerical model broadens possibilities of predicting the energetic effects even for the thin uncut chips. The original methodology of simultaneous determination of the fracture toughness and of the shear yield strength on the basis of cutting forces (or cutting power) is discussed in this paper. The experimental data usable for computation can be easily obtained while cutting wood with rotating tool, such as circular saw or router bit. The results generated include both fracture toughness and shear yield stresses in the shear plane, separately for two anatomical directions of wood. The simplicity and reliability of this method provides wide range of practical applications, including structural health assessment of the timber structures.