Influence of moisture content on the dynamic modulus of elasticity

Authors

DOI:

https://doi.org/10.33448/rsd-v11i11.33687

Keywords:

Bending test; Non-destructive test; Pinus spp. wood; Frequency; Fiber saturation.

Abstract

Pinus forests are the second most planted in Brazil and the wood obtained from them is mainly used as structural elements in the civil construction sector. The Brazilian standard that deals with calculations of wooden structures projects recommends the use of wood in the range of 10% to 20% of moisture content. Thus, this study aimed to present an investigation about the influence of moisture content on the static modulus of elasticity (MOEst) of wooden beams by transverse vibration tests. The MOEst was evaluated by static bending tests and transverse vibration tests for various moisture content. The transverse vibration test was performed in a free condition using an accelerometer and an impulse hammer, and the dynamic modulus of elasticity (MOEd) was determined from the frequency of the first bending vibration mode. A total of 20 wooden beams were obtained from freshly cut Pinus spp. logs with initial high moisture content were used, with nominal dimensions of 5 cm × 10 cm × 200 cm (thickness × width × length). It was observed that the MOEd is also affected by moisture content according to the non-linear regression model. There were significant changes in the dynamic modulus of elasticity (MOEd) for the moisture contents (M) below 25% (near the fiber saturation point - FSP).

References

Associação Brasileira de Normas Técnicas.(2022). NBR 7190-1: Projeto de estruturas de madeira: Critérios de dimensionamento.

Almeida, J. P. B., Aquino, V. B. M., Wolenski, A. R. V., Campos, C. I., Molina, J. C., Chahud, E., Lahr, F. A. R., & Christoforo, A. L. (2020). Analysis of relations between the moduli of elasticity in compression, tension, and static bending of hardwoods. BioResources, 15(2), 3278-3288. https://doi.org/10.15376/biores.15.2.3278-3288

American Society for Testing and Materials. D-198: Standard test methods of static tests of lumber in structural sizes, (2009).

Barrett, J. D., & Hong, J.-P. (2010). Moisture content adjustments for dynamic modulus of elasticity of wood members. Wood Science and Technology, 44(3), 485-495. https://doi.org/10.1007/s00226-009-0292-z

Carreira, M. R., Dias, A. A., & Segundinho, P. G. de A. (2017). Nondestructive evaluation of Corymbia citriodora logs by means of the free transverse vibration test. Journal of Nondestructive Evaluation, 36(2), 26. https://doi.org/10.1007/s10921-017-0401-0

Carreira, M. R., & Segundinho, P. G. de A. (2012). Determination of the E/G ratio of wood logs using transverse vibration. Wood Research, 57(2), 207-220.

Carreira, M. R., Segundinho, P. G. de A., Lahr, F. A. R., Dias, A. A., & Calil Júnior, C. (2012). Bending stiffness evaluation of Teca and Guajará lumber through tests of transverse and longitudinal vibration. Acta Scientiarum. Technology, 34(1), 27-32. https://doi.org/10.4025/actascitechnol.v34i1.10728

Cheng, L., Dai, J., Yang, Z., Qian, W., Wang, W., Chang, L., Li, X., & Wang, Z. (2020). Theoretical and experimental research on moisture content and wood property indexes based on nondestructive testing. BioResources, 15(1), 1600-1616.

Cho, C. L. (2007). Comparison of three methods for determining Young’s modulus of wood. Journal of Forest Science, 22, 297-306.

Chui, Y. H. (1991). Simultaneous evaluation of bending and shear moduli of wood and the influence of knots on these parameters. Wood Science and Technology, 25(2). https://doi.org/10.1007/BF00226812

Clough, R. W., & Penzien, J. (2003). Dynamics of structures. Berkeley, USA.

França, F. J. N., Seale, R. D., Ross, R. J., Shmulsky, R., & França, T. S. F. A. (2018). Using transverse vibration nondestructive testing techniques to estimate stiffness and strength of southern pine lumber (p. 8). Department of Agriculture, Forest Service, Forest Products Laboratory.

He, J., & Fu, Z. F. (2001). Modal analysis. Butterworth-Heinemann.

McConnell, K. G., & Varoto, P. S. (2008). Vibration testing: theory and practice. John Wiley & Sons.

Medeiros Neto, P. N., Paes, J. B., & Segundinho, P. G. de A. (2016). Determinações dos módulos de elasticidade e ruptura de madeiras por técnicas não destrutivas e destrutiva. Scientia Forestalis, 44(111), 683-690. https://doi.org/10.18671/scifor.v44n111.14

Segundinho, P. G. de A., Cossolino, L. C., Pereira, A. H. A., & Calil Junior, C. (2012). Aplicação do método de ensaio das frequências naturais de vibração para obtenção do módulo de elasticidade de peças estruturais de madeira. Revista Árvore, 36(6), 1155-1162. https://doi.org/10.1590/S0100-67622012000600016

Segundinho, P. G. de A., Zangiácomo, A. L., Carreira, M. R., Dias, A. A., & Lahr, F. A. R. (2013). Avaliação de vigas de madeira laminada colada de cedrinho (Erisma uncinatum Warm.). Cerne, 19(3), 441-449. https://doi.org/10.1590/S0104-77602013000300011

Souza, A. M., Nascimento, M. F., Almeida, D. H., Lopes Silva, D. A., Almeida, T. H., Christoforo, A. L., & Lahr, F. A. R. (2018). Wood-based composite made of wood waste and epoxy based ink-waste as adhesive: A cleaner production alternative. Journal of Cleaner Production, 193, 549-562. https://doi.org/10.1016/j.jclepro.2018.05.087

Teixeira, D. E. (2016). Evaluation of maximum strength and modulus of elasticity of Douglas-Fir lumber in axial to grain tension by two nondestructive techniques. Ciência Da Madeira, 7(1), 1-6. https://doi.org/10.12953/2177-6830/rcm.v7n1p1-6

Timoshenko, S. (2007). Vibration problems in engineering. John Wiley & Sons.

Unterwieser, H., & Schickhofer, G. (2011). Influence of moisture content of wood on sound velocity and dynamic MOE of natural frequency- and ultrasonic runtime measurement. European Journal of Wood and Wood Products, 69(2), 171-181. https://doi.org/10.1007/s00107-010-0417-y

Downloads

Published

21/08/2022

How to Cite

CARREIRA, M. R. .; SEGUNDINHO, P. G. de A. .; GONÇALVES, F. G.; PAES, J. B. .; DIAS, A. A. .; MEDEIROS NETO, P. N. de .; MASTELA, L. da C. .; LOPEZ, Y. M. . Influence of moisture content on the dynamic modulus of elasticity. Research, Society and Development, [S. l.], v. 11, n. 11, p. e232111133687, 2022. DOI: 10.33448/rsd-v11i11.33687. Disponível em: https://rsdjournal.org/index.php/rsd/article/view/33687. Acesso em: 26 nov. 2024.

Issue

Section

Engineerings