On the identification of earlywood and latewood radial elastic modulus of Pinus pinaster by digital image correlation: a parametric analysis

Pereira, João Luís; Xavier, José; Ghiassi, Bahman; Lousada, José; Morais, José

Abstract

This work addresses the reconstruction of strain gradient fields at the wood growth ring scale from full-field deformation measurements provided by digital image correlation. Moreover, the spatial distribution of the earlywood and latewood radial modulus of elasticity is assessed. Meso-scale tensile tests are carried out on Pinus pinaster Ait. Wooden specimens oriented in the radial–tangential plane under quasi-static loading conditions. A parametric analysis of the twodimensional digital image correlation extrinsic and intrinsic setting parameters is performed, in a balance between spatial resolution and resolution. It is shown that the parametric module is an effective way to quantitatively support the choice of digital image correlation parameters in the presence of the high deformation gradient fields generated by the structure–property relationships at the scale of observation. Under the assumption of a uniaxial tensile stress state, the spatial distribution of the radial elastic modulus across the growth rings is obtained. It is observed that the ratio of the radial modulus of elasticity between latewood and earlywood tissues can vary significantly as a function of the digital image correlation parameters. It is pointed out, however, that a convergence value can be systematically established. Effectively, earlywood and latewood stress–strain curves are obtained and elastic properties are determined assuming the converged digital image correlation setting parameters.

Citation

Pereira, J. L., Xavier, J., Ghiassi, B., Lousada, J., & Morais, J. (in press). On the identification of earlywood and latewood radial elastic modulus of Pinus pinaster by digital image correlation: a parametric analysis. Journal of Strain Analysis for Engineering Design, https://doi.org/10.1177/0309324718786351

• Journal Article Type: Article
• Acceptance Date: Jun 8, 2018
• Online Publication Date: Jul 11, 2018
• Deposit Date: Jul 23, 2018
• Publicly Available Date: Jul 23, 2018
• Journal: Journal of Strain Analysis for Engineering Design
• Print ISSN: 0309-3247
• Electronic ISSN: 2041-3130
• Publisher: SAGE Publications
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1177/0309324718786351
• Keywords: Wood, digital image correlation, earlywood, latewood, mechanical tensile test
• Public URL: https://nottingham-repository.worktribe.com/output/945857
• Publisher URL: http://journals.sagepub.com/doi/abs/10.1177/0309324718786351?journalCode=sdjb