Comportamiento viscoelástico de la madera de Prosopis sp.

Sotomayor Castellanos, Javier Ramón; Villaseñor Aguilar, José María; Sotomayor Castellanos, Javier Ramón; Villaseñor Aguilar, José María

doi:10.21829/myb.2006.1221239

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Madera y bosques

versión On-line ISSN 2448-7597versión impresa ISSN 1405-0471

Madera bosques vol.12 no.2 Xalapa sep. 2006

https://doi.org/10.21829/myb.2006.1221239

Artículos científicos

Comportamiento viscoelástico de la madera de Prosopis sp.

Javier Ramón Sotomayor Castellanos¹

José María Villaseñor Aguilar¹

^¹ Universidad Michoacana de San Nicolás de Hidalgo, Facultad de Ingeniería en Tecnología de la Madera Francisco J Múgica s/n, Edificio “D”, Planta Alta, Ciudad Universitaria Morelia A.P. núm. 580, Morelia 58000 Michoacán, México. Tel. 4433223500 ext. 3064 y 3057, Fax 4433223500, ext 3056 madera999@yahoo.com, osmavia@yahoo.com.mx

Resumen:

Los elementos estructurales de madera sometidos a cargas permanentes sufren deformaciones, lo que denota un carácter viscoso del material. Con el objeto de asegurar la fiabilidad de la estructura es necesario anticipar un comportamiento conjunto que resulta de la respuesta elástica y del comportamiento diferido de la madera. El objetivo de la investigación es demostrar el carácter viscoelástico de la madera, manifestado por la diferencia entre los valores del Módulo de Elasticidad estático y dinámico de una muestra de probetas normalizadas de Prosopis sp. Se realizaron pruebas no destructivas de flexión transversal con dos variantes: vibración en apoyos simples (ensayo dinámico) y flexión en tres puntos (ensayo estático). Los resultados demostraron que el Módulo de Elasticidad estático (MOE) es un buen predictor de Módulo de Elasticidad dinámico (Ed) y viceversa. Además, el alto coeficiente de correlación encontrado entre estos parámetros, postula que si aumenta el valor del MOE de la madera de Prosopis sp., su valor de Ed se incrementa proporcionalmente. Los ensayos dinámicos practicados resultaron ser confiables, fueron más rápidos y sus parámetros medidos fueron más repetitivos en comparación con los ensayos estáticos. La investigación fue un estudio de caso y una consecuencia de estos resultados es que la aplicación de la metodología es posible para otras especies y dimensiones de probetas.

Palabras clave: Módulo de Elasticidad estático y dinámico; Prosopis; viscoelasticidad

Abstract:

Wooden structural elements that support permanent loads bear mechanical strains. This indicates the viscoelastic nature of this material. In order to guarantee the structure’s reliability it is necessary to predict the elastic and viscous response of wood in service. The objective of this research is to show the viscoelastic nature of wood, which in turn is manifested by the difference between the Static and Dynamic Modulus of Elasticity values of a standard sample of Prosopis sp. wood. Non-destructive tests were carried out by following two procedures: transverse flexural vibration and static bending. Results showed that the Static Modulus of Elasticity (MOE) is a good predictor of the Dynamic Modulus of Elasticity (Ed) and viceversa. In addition, the high coefficient of correlation found between these parameters denotes that if the value of MOE of Prosopis sp. wood increases, the value of its Ed increases proportionally. The dynamic tests were reliable, fast and the parameters measured were more repetitive in contrast with the Static tests. This research was a case study. As a consequence of this study, the methodology for studying other wood species with different specimen’s geometry is possible.

Keywords: Static and dynamic Modulus of Elasticity; Prosopis; viscoelasticity

Referencias

American Institute of Timber Construction. 1994. Timber construction manual. 4^a Ed. John Wiley & Sons, Inc. EUA. 904 p. [ Links ]

Ashby, M.F. 1999. Materials selection in mechanical design. 2^a Ed. Butterworth-Heinemann, Gran Bretaña. 502 p. [ Links ]

Beall, F.C. 1999. Future of nondestructive evaluation of wood and wood-based materials. The e-Journal of Nondestructive Testing & Ultrasonics 4 (11). 9 p. Disponible en: http://www.ndt.net. [ Links ]

Bodig, J. 1994. NDE of wood in North America - Concepts and applications. In: First European Symposium on Nondestructive Evaluation of Wood. University of Forestry and Wood Science. Hungría. 15 p. [ Links ]

Bodig, J. y J.R. Goodman. 1973. Prediction of elastic parameters for wood. Wood Science (5)4:249-264. [ Links ]

Bodig, J. y B.A. Jayne. 1993. Mechanics of wood composites. Kreiger Publishing Company, EUA. 712 p. [ Links ]

Forest Products Laboratory. 1999. Wood handbook. Wood as an engineering material. Gen. Tech. Rep. FPL-GTR-113. Department of Agriculture. Forest Service. Forest Products Laboratory. EUA. 463 p. [ Links ]

Goens, E. 1931. Determination of Young’s modulus from flexural vibrations. Annalen der Physik 11(6):649-678. [ Links ]

Görlacher, R. 1984. Ein neues Messverfahren zur Bestimmung des Emodulus von Holz. Holz als Roh-und Werkstoff (42):212-222. [ Links ]

Guitard, D. 1987. Mécanique du matériau mois et composites. CEPADUES-EDITIONS, Francia. 238 p. [ Links ]

Guitard, D. y F. El Amri. 1987. Modèles prévisionnels de comportement élastique tridimensionnel pour les bois feuillus et les bois résineux. Annales des Sciences Forestières 44(3):335-358. [ Links ]

Haines, D.W., J.M. Leban y C. Herbé. 1996. Determination of Young`s modulus for spruce, fir and isotropic materials by the resonance flexure method with comparisons to static flexure and other dynamic methods. Wood Science and Technology (30):253-263. [ Links ]

Hearmon, R.F.S. 1966. Theory of the vibration testing of wood. Forest Products Journal 16(8):29-40. [ Links ]

Ilic, J. 2001. Relations among the dynamic and static elastic properties of air-dry Eucalyptus delegatensis R. Baker. Holz als Roh- und Werkstoff (59):169-175. [ Links ]

International Organization for Standardization ISO 3129-1975 (E). 1975a. Wood - sampling methods and general requirements for physical and mechanical tests. ISO Catalog 79 Wood technology; 79.040 Wood, sawlogs and saw timber. International Organization for Standardization (ISO). Disponible en: www.iso.ch/iso/en/ISOOnline.openerpage [ Links ]

International Organization for Standardization ISO 3349-1975 (E). 1975b. Wood - Determination of modulus of elasticity in static bending. ISO Catalog 79 Wood technology; 79.040 Wood, sawlogs and saw timber. International Organization for Standardization (ISO). Disponible en: www.iso.ch/iso/en/ISOOnline.openerpage. [ Links ]

Jayne, B.A. 1959. Vibrational properties of wood as indices of quality. Forest Products Journal 9(11):413-416. [ Links ]

Kaiserlik, J.H. y R.F. Pellerin. 1977. Stress wave attenuation as an indicator of lumber strength. Forest Products Journal 27(6):39-43. [ Links ]

Kollmann, F. y H. Krech. 1960. Dynamische Messung der elastischen Holzeigenschaften und der Dämpfung. Holz Roh-Werkstoff (18):41-54. [ Links ]

Kollmann, F.P. y W.A. Côté. 1968. Principles of wood science and technology. Volume I: Solid wood. Springer-Verlag, Alemania. 592 p. [ Links ]

Lemmens, J.W. (s/f). Operating instructions for the GrindoSonic MK5 “Industrial” Instrument. J.W. Lemmens, Inc. EUA. 25 p. [ Links ]

Machek, L., H. Militz y R. Sierra-Alvarez. 2001. The use of an acoustic technique to assess wood decay in laboratory soil-bed tests. Wood Science and Technology 34(6):467-472. [ Links ]

Panshin, A.J. y C. De Zeeuw. 1964. Textbook of wood technology. Volume I. McGraw-Hill, Inc. EUA. 705 p. [ Links ]

Pellerin, R.F. 1965. A vibrational approach to nondestructive testing of structural lumber. Forest Products Journal 15(3):93-101. [ Links ]

Perstorper, M. 1992. Predicting the stiffness of structural timber using dynamic modal tests. In: Proceedings of IUFRO S5.02 Timber Engineering 1992 Conference. Francia. pp:305-324. [ Links ]

Ross, R.J. et al. 1977. Relationship between log and lumber modulus of elasticity. Forest Products Journal 47(2):89-92. [ Links ]

Ross, R.J. y R.F. Pellerin. 1988. NDE of wood-based composites with longitudinal stress waves. Forest Products Journal 38(5):39-45. [ Links ]

Ross, R.J. y R.F. Pellerin. 1994. Nondestructive testing for assessing wood members in structures: A review. Gen. Tech. Rep. FPL-GTR-70 (Rev.). Department of Agriculture. Forest Service. Forest Products Laboratory. EUA. 40 p. [ Links ]

Sandoz, J.L. 2000. Wood testing using Acousto-Ultrasonic. Publication IBOIS 00:23, Institut de Statique et Structures IBOIS. Construction en bois. In: Proceedings of the World Conference on Timber Engineering (WCTE 2000), Whistler Resort, British Columbia, Canada. 6 p. [ Links ]

Sandoz, J.L. 2002. High performance timber by ultrasonic grading. Publication IBOIS 00:20, Institut de Statique et Structures IBOIS. Construction en Bois. In: Proceedings of the 7^th World Conference on Timber Engineering (WCTE 2002). MARA University of Technology, Selangor, Malasia. 7 p. [ Links ]

Timoshenko, S., D.H. Young y W. Weaver. 1994. Vibration problems in engineering. John Wiley, Nueva York. [ Links ]

Recibido: 08 de Julio de 2005; Aprobado: 17 de Noviembre de 2005

Este es un artículo publicado en acceso abierto bajo una licencia Creative Commons