Non-Destructive Evaluation of Reclaimed Timber Using Visual Grading, Dynamic Excitation, Mechanical Testing, and X-ray CT-Based Modelling

This preprint presents a multimodal evaluation framework for reclaimed structural timber, combining X-ray computed tomography (CT), visual grading, dynamic excitation, four-point bending tests, and two classes of computational models (continuum-mechanics models and finite element analyses). Using 56 full-length reclaimed beams, the study compares the spatial sensitivity and predictive performance of established non-destructive techniques and CT-derived stiffness and density fields. The results demonstrate how voxel-resolved CT information can quantify stiffness- and defect-related variability and how these indicators relate to global and local mechanical performance.

The analyses include:
• Full-resolution CT-derived density and fibre-orientation fields
• Longitudinal and transversal dynamic excitation measurements
• Destructive and non-destructive mechanical bending tests
• Visual grading according to INSTA 142, UNI 11119, and NS 3691-3
• CT-based continuum-mechanics stiffness models
• CT-informed finite element models with orthotropic material fields
• Correlation, regression, and indicator-comparison analyses at beam and zone scales

All underlying CT volumes, derived stiffness fields, CM and FE model outputs, profile-level results, and statistical analysis plots are openly available in the associated dataset:

Dataset:
Huber, J.A.J. et al. (2025). Multimodal Reclaimed Timber Dataset: X-ray CT Volumes, Visual Grading, Dynamic Tests, Mechanical Tests, and Finite Element and Continuum Model Results. Zenodo. DOI: https://doi.org/10.5281/zenodo.17682667 

This preprint should be cited together with the dataset when reusing data, analysis workflows, or modelling approaches.