Development of a constructive solution of wood columns and crossbars interfaces on metal overlays and screws

Introduction. The paper discusses the advantages and features of the main existing methods of connecting wooden columns and crossbars.

Materials and methods. It was proposed to increase the load-bearing capacity and reduce the deformability of joints by modifying the joints with the introduction of epoxy resin between the screw and the wood and between the overlay and the end of the wooden element to which it is attached and modifying the design of the overlays.

Results. As a result, a constructive solution for connecting wooden columns and crossbars was developed, which has increased reliability compared to the studied connections and is free of their disadvantages. This result was achieved due to the presence of an adhesive layer between the screw and the wood, as well as between the overlay and the wooden element, the making of notches on the sides of the overlays attached to the wooden elements, the increased length of the screws screwed into the overlay with a groove, compared to the length of the screws screwed into an overlay with a tenon, placement of holes for screws at an angle of 90° to the surface of the overlay into which the screws are screwed.

Conclusions. An urgent issue is the development of constructive solutions for connections of wooden elements, in particular the interfaces of columns and crossbars. The paper discusses the advantages and features of the main existing methods of connecting wooden columns and crossbars.

1. Chernova T., Melekhov V. Behavior of timber-timber composite structure connected by inclined screws. Magazine of Civil Engineering. 2023; 4(120):12004. DOI: 10.34910/MCE.120.4.EDN LTHOSP.

2. Leijten A., Franke S., Quenneville P., Gupta R. Bearing strength capacity of continuous supported timber beams: Unified approach for test methods and structural design codes. Journal of Structural Engineering. 2012; 138(2):266-272. DOI: 10.1061/(ASCE)ST.1943-541X.0000454

3. Leijten A.J. M., Larsen H.J., Van der Put T.A.C.M. Structural design for compression strength perpendicular to the grain of timber beams. Construction and Building Materials. 2010; 24(3):252-257. DOI: 10.1016/j.conbuildmat.2009.08.042

4. Dezhin M., Ibragimov A. Improving the reliability of the joints of wooden elements on metal linings. E3S Web of Conferences. 2023; 402:10005. DOI: 10.1051/e3sconf/202340210005

5. Dezhin M., Ibragimov A. Increasing the bearing capacity of the joints of wooden elements on metal plates. Lecture Notes in Civil Engineering. 2023; 341-348. DOI: 10.1007/978-3-031-10853-2_32

6. Dezhin M.A., Ibragimov A.M. The study of the nature of the deformability of wooden elements joints on metal lips with the application of screws. BST: Bulletin of the Construction Equipment. 2023; 1(1061):52-53. EDN XQUFJH. (rus.).

7. Dezhin M.A. Bearing capacity and deformability of joints of wooden elements on metal plates using screwed in screws. Engineering Journal of Don. 2021; 6(78):264-271. EDN FUXSTM. (rus.).

8. Dezhin M.A. Estimation of the influence of the application of epoxy glue on the strength indicators and deformation of joints of wooden elements on metal plates with the application of screws. BST: Bulletin of the Construction Equipment. 2022; 2(1050):28-30. EDN INMZAF. (rus.).

9. Madsen B., Hooley R., Hall C. A design method for bearing stresses in wood. Canadian Journal of Civil Engineering. 1982; 9(2):338-349. DOI: 10.1139/l82-035

10. Leijten A. The bearing strength capacity perpendicular to grain of Norway spruce — Evaluation of three structural timber design models. Construction and Building Materials. 2016; 105:528-535. DOI: 10.1016/j.conbuildmat.2015.12.170

11. Hoffmeyer P., Damkilde L., Pedersen T. Structural timber and glulam in compression perpendicular to grain. Holz als Roh- und Werkstoff. 2000; 58(1-2):73-80. DOI: 10.1007/s001070050390

12. De Santis Y., Fragiacomo M. Timber-to-timber and steel-to-timber screw connections: Derivation of the slip modulus via beam on elastic foundation model. Engineering Structures. 2021; 244:112798. DOI: 10.1016/j.engstruct.2021.112798

13. Hamid Mirdad M., Jucutan K., Niederwestberg J., Hei Chui Y. Embedment and withdrawal stiffness predictions of self-tapping screws in timber. Construction and Building Materials. 2022; 345:128394. DOI: 10.1016/j.conbuildmat.2022.128394

14. Linkov V.I. Increasing the bearing capacity of connections on inclined screwed rods. Engineering Journal of Don. 2020; 11(71):339-346. EDN JSHPHD. (rus.).

15. Linkov V.I. The stress condition of inclined metal rods in the timber elements of the built-up section. Engineering journal of Don. 2019; 1(52):159. EDN OBUTSB. (rus.).

16. Linkov V.I. Bearing capacity and deformability of ISR-connections of wooden elements at different positions of the screwed-in rod. Textile Industry Technology (Series: Proceedings of Higher Educational Institutions). 2021; 4(394):179-185. DOI: 10.47367/0021-3497_2021_4_179.EDN YMIRHW. (rus.).

17. Linkov V.I. Connections on inclined screwed rods in wooden beams for the reconstruction of textile industry buildings. Textile Industry Technology (Series: Proceedings of Higher Educational Institutions). 2017; 3(369):212-217. EDN ZIWDAV. (rus.).

18. Linkov V.I. Use of soft hardwood in wooden elements of composite section on inclined metal rods. Textile Industry Technology (Series: Proceedings of Higher Educational Institutions). 2019; 2(380):153-158. EDN SQMHPE. (rus.).

19. Linkov V.I. On the question of designing composite wooden beams on inclined metal rods for coatings of reconstructed in textile industry. Textile Industry Technology (Series: Proceedings of Higher Educational Institutions). 2018; 3(375):84-89. EDN VJQDJY. (rus.).

20. Syuj Yu. Increasing the load-bearing capacity of connections between wooden structural elements on metal plates using a metal toothed plate : thesis of candidate of technical sciences. St. Petersburg, 2015; 198. EDN XZRHZB. (rus.).