Elasto-mechanical characterisation of yew and spruce wood with regard to structure-property relationships

For centuries, Common yew (Taxus baccata L.) has been well known for its extraordinary longitudinal elasticity and toughness. Its wood was used for certain weapons (e.g. longbows) requiring these material properties, particularly the low Young’s modulus and at the same time a high stretchability parallel to the grain. The few available literature references also indicate a high elasticity. Indisputably, there are further elastic softwood species, but none of them have a similarly high raw density as yew (620-720 kg/m3). Thus, yew holds an exceptional position, especially since there is usually a strong species-spanning positive interrelation between density and Young’s modulus. The reasons for this compliant response of yew despite its high density were as yet unknown.