Comportamiento en vibraciones longitudinales y transversales de vigas de madera antigua de Picea abies
Longitudinal and transversal vibrations behavior of old Picea abies wood beams
Resumen
El objetivo fue evaluar el comportamiento dinámico de la madera de Picea abies. Se realizaron pruebas de vibraciones longitudinales y transversales en cinco vigas con una antigüedad de cien años. Se propone un protocolo experimental para evaluar la resistencia mecánica y la capacidad de amortiguamiento de vibraciones mecánicas de las vigas empleando pruebas no destructivas. Se calcularon el módulo de elasticidad y el coeficiente de amortiguamiento correspondientes a las direcciones longitudinal, radial y tangencial de la madera. Los resultados indicaron una relación de anisotropía de los módulos de elasticidad del orden de ET EL > ER, con coeficientes de variación aceptables en experimentación de la madera. Igualmente, los coeficientes de amortiguamiento mostraron una anisotropía de: tan T > tan R > tan L. Se concluyó que las vigas antiguas tienen propiedades mecánicas similares a las de madera recientemente cortada. Los parámetros determinados pueden servir como referencia para el análisis estructural de elementos de madera presentes en edificaciones antiguas. Sin embargo, es necesario considerar las condiciones de cada caso de estudio en particular.
Abstract
The objective was to evaluate the dynamic behavior of Picea abies wood. Longitudinal and transversal vibrations tests were performed in five wood beams with an antiquity of one hundred years. An experimental protocol is proposed to evaluate the mechanical strength and the damping capacity of the mechanical vibrations of beams using nondestructive methods. The modulus of elasticity and the damping coefficient corresponding to the longitudinal, radial and tangential directions of the wood were calculated. The results showed an anisotropy ratio of the moduli of elasticity in the order of ET EL > ER, with acceptable variation coefficients in experimental wood. Similarly, the damping coefficients showed anisotropy of: T > tan R > tan L. It was concluded that the old wood beams have similar mechanical properties to those of recently cut wood. The determined parameters can serve as a reference for the structural analysis of wooden elements present in old buildings. Nonetheless, it is necessary to consider the conditions of each case study in particular.
Keywords: frequency, modulus of elasticity, damping coefficient, anisotropy, non destructive testing.
Citas
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