PSI - Issue 54

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Karolak A., Jasieńko J. / Structural Integrity Procedia 00 (2019) 000 – 000

Anna Karolak et al. / Procedia Structural Integrity 54 (2024) 460–467 © 2023 The Authors, Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the ICSI 2023 organizers Keywords: carpentry joints; mechanical behaviour; flexural elements 1. Introduction Wood has long been one of the most widely used materials in construction. Despite common belief, it is a fairly long-lasting material that, with appropriate use and maintenance, can serve for many years according to Ross (2002). A great number of wooden buildings – timber structures with carpentry joints between their elements have therefore continued to survive to the present day. Nowadays some of them are in need of conservation, strengthening or repair works. Knowledge gathering on carpentry joints applied in historical timber structures is one of the most crucial issues in the analysis as these joints are most often key points in the structure as a whole. The role of the joints is to ensure the rights placement of the structural elements between each other and in the whole structure, to transfer the loads between the individual structural elements, and to tie the whole structure together. What is more, often, the joints are the testimony of the art and craftsmanship of the creators as stated in Jasieńko et al. (2014). Therefore, there is need to to perform research on the mechanical work of the carpentry joints to enable the proper understanding and describing their behaviour, and then designing appropriate strengthening accordingly to ensure that these wooden structures will last for many more years. Longitudinal joints, used to achieve the required length of the timber beam or other structural element, may have taken many various forms in accordance with the place and time of their origin and the role they were intended to serve in the structure – what type of loading they would carry, what was described i.a. by Karolak et al (2020). Such joints are referred to in the literature as scarf and splice joints. In case of the frame timber structures the joints were used in order to extend the capping beams or foundation beams and different roof elements, such as rafter beams, when needed. Nowadays, the joints are primarily used to restore the historical joints or to supplement material in historical structural elements, Corradi et al. (2019). Moreover, in many cases the structural solutions used in an object present a high historical and artistic value in themselves, what was stated i.a. by Rapp (2015). One of a very interesting examples of the longitudinal joint is a stop-splayed scarf joint (lightning sing, ‘Trait -de Jupiter’ ), described i.a. by Perez (2003), Tampone et al. (2006), Parisi et al. (2008) and Perria (2017). Another examples are the built-up beams (composite teethed beams), described i.a. by Rug et al. (2012), (2015) and Mirabella Roberti (2013). What is more, the joints of this type were also used in the historical structures in ancient times, where Roman bridges can be cited as an example, and also in the Italian Renaissance, where they can be found in the designs of the masters like Leonardo da Vinci, what was shown by Mirabella-Roberti (2013), and Leon Battista Alberti, Alberti (1965). The examples of various forms of longitudinal connections are shown in Fig. 1 and Fig. 2. 461

Figure 1 – Exemplary forms of historical carpentry joints: a) simple lap, b) inclined lap, c) tabled splice, d) stop-splayed scarf

a)

b)

Figure 2 – Drawings of scarf and splice carpentry joints according to a) L. da Vinci, presented in Mirabella-Roberti (2013), b) L.B. Alberti, presented in Alberti (1965)