DEVELOPING A MATHEMATICAL MODEL TO DETERMINE THE STRENGTH OF SPLICED LATHS MADE FROM POST-CONSUMER WOOD FOR ROOF STRUCTURES IN BUILDINGS
Keywords:
reused wood, finger joint, bending strength, roof structures, regression model, circular economy, parameter optimizationAbstract
The article presents a study on the bending strength of finger-jointed laths made from reused wood (RW) for roof structural applications. The relevance of this research lies in promoting resource-efficient technologies and the principles of the circular economy in construction. The variability of mechanical properties in secondary timber creates challenges in predicting its strength performance. To quantify the influence of geometric parameters – lath width (B) and finger length (L) – on bending strength, experimental tests were performed, and a second-order two-factor regression model was developed. The model revealed a statistically significant effect of both factors and confirmed a synergistic interaction: the bending strength increases when both width and finger length grow simultaneously. The optimal parameters achieving maximum strength (79.83 MPa) are B=64 mm and L=24 mm. It was demonstrated that reused wood can be effectively transformed into full-length structural elements with strength exceeding 70 MPa, meeting the normative requirements for roof load-bearing members.
The practical significance of the study lies in enabling optimization of production parameters for finger-jointed elements, improving material utilization efficiency, and reducing production costs. The recommended parameter ranges – lath width 56–64 mm and finger length 18–24 mm – can be applied in manufacturing standards, technical specifications, and process charts for the woodworking industry. The results contribute to sustainable and resource-efficient timber construction, reducing environmental impact and establishing a foundation for further studies on the durability and long-term performance of reused-wood joints.
References
DBN V.2.6-161:2017. Wooden structures. Basic provisions. Kyiv: Ministry of Regional Development of Ukraine, 2017. 117 p.
DSTU EN 15497:2019. Structural finger jointed solid timber – Performance requirements and minimum production requirements. Kyiv: Ukrainian Research and Training Center, 2019.
DSTU-N B V.2.6-217:2016. Guidelines for the design of building structures made of solid and glued timber. Kyiv: Ministry of Regional Development of Ukraine, 2016. 35 p.
EN 15497:2014. Structural finger jointed solid timber – Performance requirements and minimum production requirements, 2014.
EN 385:2001. Finger jointed structural timber – Performance requirements and minimum production requirements, 2001. 16 p.
Gayda S. V. Analysis of the trend of the main indicators of the wood processing industry in the context of the circular economy. Forestry, Forest, Paper and Woodworking Industry. 2024. Vol. 50. P. 4–15. https://doi.org/10.36930/42245001.
Gayda S. V. Modeling properties of blockboards made of post-consumer wood on the basis of the finite element method. Forestry, Forest, Paper and Woodworking Industry. 2015. Vol. 41. P. 39–49. https://doi.org/10.36930/42154106.
Gayda S. V. Modern technologies and equipment for splicing. Woodbusiness. 2005. Vol. 2. P. 32–41.
Gayda S. V. Modern technologies of wooden house construction. Woodbusiness. 2003. Vol. 4. P. 33–44.
Gayda S. V. Progressive technologies of longitudinal wood splicing. Equipment and Tools for Professionals. 2004. Vol. 5. P. 10–19.
Gayda S. V. Promising technologies of longitudinal splicing. Woodbusiness. 2004. Vol. 2. P. 34–45.
Gayda S. V. The technologies and recommendations for the use of post-consumer wood in wood processing. Forestry, Forest, Paper and Woodworking Industry. 2013. Vol. 39 (1). P. 48–67. https://doi.org/10.36930/42133909.
Gayda S. V. Using fuzzy expert systems for decision support in the process of post-consumer wood sorting. Forestry, Forest, Paper and Woodworking Industry. 2017. Vol. 43. P. 5–20. https://doi.org/10.36930/42174301.
Gayda S. V., Ferents O.B. Comparative analysis of alternative technologies for wooden house construction. Forestry, Forest, Paper and Woodworking Industry. 2025. Vol. 51. P. 49–63. https://doi.org/10.36930/42255104
Gayda S. V., Kiyko O. A. Determining the regime parameters for the surface cleaning of post-consumer wood by a needle milling tool. Eastern-European Journal of Enterprise Technologies. 2020. 5 (1 (107)). P. 89–97. https://doi.org/10.15587/1729-4061.2020.212484.
Gayda S. V., Lesiv L E. Mathematical model of forecasting volumes of post-consumer wood production. Forestry, Forest, Paper and Woodworking Industry. 2023. Vol. 49. P. 33–47. https://doi.org/10.36930/42234903.
Gayda S. V., Lesiv L. E. A determination and comparison of properties of post-consumer wood of the basic conifers. Forestry, Forest, Paper and Woodworking Industry. 2019. Vol. 45. P. 39–46. https://doi.org/10.36930/42194506.
Kondratyuk S. Ya. Resistance of materials and structural mechanics of wooden structures. Kyiv: KNUBA, 2015.
Lesiv L. E., Gayda S. V. Building a strength model of spliced billets made from post-consumer fir wood. Proceedings of scientific conference (Kharkiv, October 7–8, 2024). 2024. P. 187–189.
Lesiv L. E., Gayda S. V., Salapak L. V. Development of a mathematical model of the strength of joined preparations from post-consumer fir wood. Forestry, Forest, Paper and Woodworking Industry. 2024. Vol. 50. P. 16–28. https://doi.org/10.36930/42245002
Medvid L. V. Post-consumer wood – an additional reserve of raw materials for construction materials. Forestry, Forest, Paper and Woodworking Industry. 2021. Vol. 47. P. 34–46. https://doi.org/10.36930/42214706.
Mykhailovskyy D., Komar M., Sklyarova T., Bondarchuk B. The use of glued and cross-glued timber in reconstruction and new construction. Building structures. Theory and practice. 2024. Vol. 15. P. 54–65.
Ridoutt B. G. et al. Environmental impacts of engineered wood products. Journal of Cleaner Production. 2019. Vol. 234.
Savchuk O. V. The use of glued beams in bridge construction. Roads and Bridges, 2021.
Sendziuk V. I., Gerasimenko I. V. Building structures made of wood and plastics. Lviv: UNFU, 2017.
Thelandersson S., Larsen H. J. (Eds.). Timber Engineering. Chichester: John Wiley & Sons, 2003.
