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

Abstract

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 GR(Δau). 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.