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Non-destructive evaluation of the bending behaviour of in-service pine timber structural elements

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Abstract

An essential step while assessing the performance of existing timber structures is the allocation of strength and stiffness values to the timber members. In spite of the importance of this step and the research effort already made, the evaluation of timber structural members in-service is still performed in most cases based only on visual strength grading rules. This paper addresses the possibility of applying a procedure based on visual assessment and ultrasonic testing for predicting the bending strength and stiffness of timber elements in-service. This possibility can support a more accurate structural performance analysis of timber structures. The basis of the procedure is explained and the results of its application to maritime pine timber (Pinus pinaster Ait.) beams are shown. The setting-up of the procedure includes data from former studies and new experimental data. A validation is carried out on two extra samples (not used in the setting-up process) by comparing the global modulus of elasticity and the bending strength of maritime pine timber obtained following EN 408 with the predicted value given by the proposed procedure. The application of this procedure provided a good agreement between the predicted and the experimental values of global modulus of elasticity. Regarding the bending strength, the results indicate that more precise parameters, or choice of parameters, need to be defined in order to address the real effect of knots.

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Acknowledgments

The authors gratefully acknowledge the support given by Fundação para a Ciência e a Tecnologia (FCT) to the project “Safety evaluation of timber structures through non-destructive methods and stochastic analysis” under contract PTDC/ECM/66527/2006.

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Authors and Affiliations

  1. Timber Structures Division, Laboratório Nacional de Engenharia Civil, Av. do Brasil, 101, 1700-066, Lisbon, Portugal

    José Saporiti Machado & Pedro Palma

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  1. José Saporiti Machado
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  2. Pedro Palma
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Correspondence to José Saporiti Machado.

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Machado, J.S., Palma, P. Non-destructive evaluation of the bending behaviour of in-service pine timber structural elements. Mater Struct 44, 901–910 (2011). https://doi.org/10.1617/s11527-010-9674-9

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