Analysis of Wood Peculiarities by Resonant Vibration Method

摘要

Most wood products meet dynamic loads. Evaluation of mechanical properties of wood in dynamic mode allows forecasting wood assortment behavior in dynamic loads zone. The article discusses modulus of elasticity research methodology and equipment for leafy and conifer (oak and spruce) rectangular wood plates (oak - 340x340x14 mm and 400x300x14 mm, spruce - 300x280x30 mm and 300x265x30 mm), glued-up panels (oak - 500x500x30 mm and 700x700x30 mm, spruce - 400x400x14 mm) and scantlings (oak - 670x60x30 mm, spruce - 400x40x14 mm). Cross-resonant vibrations method was employed for wood assortment analysis. Resonant frequencies and bend forms (modes) were evaluated. It was illustrated that through different along and across mechanical properties of wood fiber vibration of such products to the above-mentioned directions are parallel to vibration of beam-formed body. Applying theoretical calculations for beam-formed body, oak wood modulus of elasticity was estimated across (E = 900 - 2000 MPa) and along (E,= 8000 - 14000 MPa) fiber. For spruce wood, respectively, (E = 140 - 500 MPa) and (E, = 7500 - 14000 MPa). Suggested methodology and equipment can be successfully applied to analysis and quality evaluation (assortment, hunt for defects, etc.) of other products, analogical to natural wood in terms of fiber direction.