Deflection of Densified Beech and Aspen Woods as a Function of Selected Factors

Adam Sikora, Zuzana Gaffová, Rastislav Rajnoha, Anna Šatanová, Richard Kminiak

Abstract


Effects of selected factors (wood species (Beech, Aspen), degree of densification (10%, 20%), material thickness (4 mm, 6 mm, 10 mm, and 18 mm), and number of loading cycles (0, 10,000)) were analyzed relative to the bendability of densified wood. The monitored characteristics were the deflection at proportional limit (YE), deflection at maximum limit (YP), and their ratio (YE:YP). One of the main causes of unfavorable wood bending is its low deflection under tensile stress parallel to the fiber in comparison to compressive stress in the same direction. From the results it is clear that the deflection at the proportionality limit depended on all monitored factors. The deflection at the yield point was not influenced by cyclic loading, and the ratio of deflection was influenced by material thickness only. Based on this ratio, the moulding properties of material can be identified. There was a strong correlation between the two deflection limits. The results are an important foundation for progress in the production of laminated materials with specific properties for intended use.

Keywords


Cyclic loading; Laminated wood; Bend strength; Modulus of elasticity, elasticity deflection at proportional limit, deflection at maximum limit , ratio of elastic and maximum deflection

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