PSI - Issue 54

Anna Karolak et al. / Procedia Structural Integrity 54 (2024) 460–467 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

462

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As it was already mentioned, problem of the carpentry joints is considered as one of the most important issues in the analysis of the historical structures. For this reason, the problem has been studied for some time by scientists all over the world. The literature review shows that there are many studies on the most common tenon joints and notched joints, however, there is much less studies on splice and scarf joints, what was underlined by many researchers. The longitudinal connections were analysed in the United Kingdom by Hirst et al. (2009), the United States Sangree et al. (2009), (2009), in Germany by Rug et al. (2012), (2015), in the Czech Republic by Šobra et al. (2013), Arciszewska Kędzior et al. (2015), in Poland by Rapp et al. (2015), (2015), again in the Czech Republic by Fajman et al. (2015), (2018), Kunecký (2015), (2018), in Spain by Aira et al. (2016), in Italy by Ceraldi et al. (2019), and finally in Poland again by Karolak et al. (2020). Some examples of the experimental research and numerical analysis on various longitudinal joints presented in the mentioned literature. Hirst et al. (2009) analysed different forms of scarf joints that occur mainly in historical objects in England, eg the pegged scarf joint in the form of halved and bridled faces. In turn, the halved and tabled scarf joints and the keyed stop-splayed scarf joints were analysed by Sangree and Schafer (2009), (2009). Rug et al. conducted studies on the composite teethed beams with stop-splayed scarf joints (2012), (2015). In addition, Mirabella-Roberti and Bondanelli (2013) analysed composite beams jointed longitudinally using stop-splayed scarf joints. The mechanical behaviour of the scarf lap joints with inclined faces under bending loads was presented in detail by Šobra et al. (2013), Arciszewska - Kędzior et al. (2015), Fajman et al. (2015) , (2018) and Kunecký (2015), (2018). What should be underlined is the fact that almost every researcher who analysed this type of carpentry joints pointed out the need to conduct further research on the topic to obtain more complete data and more precise descriptions of the mechanical behaviour under loads and failure modes. All this information are necessary and would be helpful in order to propose the most beneficial methods of strengthening, repairing and conservating these joints in the existing historical objects. Therefore an extensive research on different longitudinal joints in the flexural elements was performed as part of the scientific project, financed by the Polish National Science Centre. 2. Materials and methods Beam models with the carpentry joints with the geometry created on the basis of the geometry of the historical joints according to the data obtained from real structures and the literature were prepared for the experimental tests. Beam models were on a technical scale, made from pine wood (Pinus sylvestris L.) of the minimum class C24 with dimensions of 360 cm in length and 12 cm x 18 cm in cross section. For the tests 7 series of 3 beams with carpentry joints of different geometry and with different additional fastening elements and 1 series of reference solid beams were prepared. The length of the joints was three times the height of the beam according to the guidelines of the carpentry art. All models for the tests with description, axonometric schemes of the joints are presented in Tab. 1. Table 1 – Models for experimental tests

Beam series

Description

A

Continuous reference beam

B Beam with simple lap joint created in vertical plane with 4 bolts; the length of the joint – 540 mm; overlap half the width of the beam – 60 mm