Mode I and II R-curves characterization of the Maritime Pine and Spruce under the same geometry

This study provides detailed data on the quasi-brittle behaviour of two softwood species, the Maritime Pine (Pinus pinaster.) and the Spruce (Picea abies.), by using R-curves. The methodology of characterization of the R-curve used in this article is an improvement of the method presented by Lespine (2007). This method is automated and based on the measurement error made on ����(������) . And the same geometry to characterize the crack propagation in mode I and in mode II. The influence of the crack plane orientation and the density on the fracture mechanisms is investigated for both species and shows a dependency of the R-curve parameters of the Maritime Pine in mode I to the crack plane orientation. The differences between Spruce and Maritime Pine are highlighted. This demonstrate the importance to characterize the quasi-brittle behaviour of each wood species in order to provide a useful data base for engineers