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Evaluation of the local dynamic modulus of elasticity in wooden tie by the stress wave method with semi-destructive estimation of density.
- Source :
- Iranian Journal of Wood & Paper Science Research; Summer2024, Vol. 39 Issue 2, p133-145, 13p
- Publication Year :
- 2024
-
Abstract
- Background and objectives: Due to the limitations of determining the remaining useful life in the components of the wooden structures at the conditions of use with destructive methods is the impossibility of calculating the modulus of elasticity due to the impossibility of removing the part from the structure. Therefore, most of the classifications during use in the components of structures such as historical buildings are based on measuring the speed of sound. In this research, to calculate the local and global density و the method of pin penetration rate in wooden tie was used to calculate the amount of the remaining useful life. Pin penetration rate was combined with stress wave and free longitudinal vibration methods. Methodology: The three beech wood (Fagus orientalis) impregnated wooden tie from Iran Railway Company with the dimensions of 15x25x260 cm, were selected and the density was measured by pin penetration method at 5 points of each wooden tie (50 cm distance between each point) and the average results of 5 points were compared with the results of ISO 13910 standard method. The stress wave test was carried out at the same 5 points of density determination by pin penetration rate method to determine the local modulus of elasticity and the results of each point were compared with the global modulus of elasticity of the beam. Longitudinal vibration test was also performed to calculate the damping factor values of the samples. Results: The results showed that there was no significant difference at the 95% level between the values calculated with both the ISO 13910 standard methods and the pin penetration rate method, and there was a favorable linear correlation between the results of the two methods. According to the results, there was no significant difference between the global sound speed of the beams and their local sound speed in any of the five measured points at the 95% level and there was a linear correlation between the values of the global sound speed and each of the five local points. There was no significant difference at the 95% level between the values of the global modulus of elasticity and the values of the local modulus of elasticity calculated in each of the five points. Also, there was a linear correlation between the values of the global modulus of elasticity and the results of the local modulus of elasticity in each of the five points. There was an exponential correlation between the values obtained from the global modulus of elasticity and the damping factor of each of the wooden tie. Conclusion: The equality of density according to the ISO 13910 standard method and the nail penetration method, as well as the equality of the modulus of elasticity calculated by the stress wave method and the free longitudinal vibration method, make it possible to obtain all the data required for required calculations without removing the part from the structure. The remaining strength of wooden components should be provided according to EN338 standard. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 17350913
- Volume :
- 39
- Issue :
- 2
- Database :
- Complementary Index
- Journal :
- Iranian Journal of Wood & Paper Science Research
- Publication Type :
- Academic Journal
- Accession number :
- 178059656
- Full Text :
- https://doi.org/10.22092/IJWPR.2023.361802.1751