Wave speed and modulus of elasticity by ultrasound and stress waves of Pinus spp. Mexican wood beams

Abstract

The wood construction industry requires data of the mechanical strength of wood with dimensions and classification suitable to be used as structural elements. This research proposes an experimental strategy for the mechanical characterization of wood beams and their application as an engineering material. The objective of the research was to determine the wave speeds and moduli of elasticity of Pinus spp. beams using ultrasound and stress waves, studying 70 Pinus spp. beams with dimensions of 0.10 m x 0.15 m in the transverse direction, 35 beams of 5 m and 35 of 6 m length. The speeds of transmission showed coefficients of variation consistent with the structural heterogeneity of wood. The values of these coefficients increased when the second-level characteristics were calculated, as in the case of the moduli of elasticity. The speed and the modulus of elasticity showed an important anisotropy character for the calculus of the mechanical strength of the beams. Likewise, the parameters calculated with the stress wave method were higher than those determined by ultrasound. The results allow concluding that theultrasound and stress wave techniques can determine the speed wave and the modulus of elasticity of Pinus spp. wood beams.