Dynamic Mechanical Analysis of Viscoelastic Properties of Softwood and Hardwood as a Natural Polymer Material

The dynamic mechanical analysis with the use of low-amplitude probing harmonic oscillations in addition to the main quasi-static load was used to determine the storage modulus E′, the loss modulus E″ and the mechanical loss coefficient tgδ. A comparative characteristic of the static and dynamic viscoelastic properties of wood of softwood (pine, spruce, larch) and hardwood (oak, linden, birch) tree species common of the Russian Federation was presented depending on the frequency of probing harmonic oscillations and the stress of the quasi-static load. The contribution of various frequencies to the formation of the total viscoelastic response of wood of softwood and hardwood species was determined, the effect of an additional oscillating load on the dynamic parameters of wood was estimated.