PSI - Issue 78

Giacomo Iovane et al. / Procedia Structural Integrity 78 (2026) 521–527

522

it is worth emphasizing that, in many cases, the size of timber members is influenced by type and number of fasteners used. With regards to Moment Resisting Frames (MRF), the mechanical behavior of joints significantly impacts both the global deformation and the failure mechanisms: the stiffness of the joints contributes to the overall structural response, while the strength influences the collapse modes. In this perspective, a mechanical characterization of joints is fundamental, but, despite this, current standards for timber constructions do not provide a mechanical classification method of timber beam-to-column joints, essential for the correct design of the joints and the prediction of the structures global behavior. To fill this gap, in Iovane et al. (2023a) a classification method of timber beam-to-column joints in terms of rotational stiffness and bending strength has been proposed. The proposal exploits the well-established classification method indicated in Eurocode 3 part 1-8 for steel structures, conveniently modified to consider the timber material features. The starting point is the overview conducted on common configurations of timber beam-to-column joints. In particular hereafter a total of 18 additional noteworthy scientific studies, since 2016, regarding experimental tests on timber beam-to-column joints, are examined. 5 main joint categories are defined on the bases of the total 46 studied joints. Finally the joint classification in terms of stiffness is provided by means of the proposed method. 2. Definition of the typological categories for common timber beam-to-column joints On the bases of the reference studies available in scientific literature, the most common timber beam-to-column joints have been grouped in the following 5 categories, schemes, with the evidence of the vertical and plane views, are shown in Figure 1, a study case for each type is shown in Figure 2: Type 1 . Connection with internal or external vertical steel plates, rectangular- or T-shaped, and fasteners; Configuration 1.1 - a rectangular steel plate is placed inside a milling at the beam end and at the column, it is connected generally through bolts (Wang et al., 2014, 2016; He and Liu, 2015; He et al., 2016; Beltran, 2016; Salem and Petrycki, 2016; Liu and Xiong, 2018; Zhan et al., 2019; Kang et al., 2022; Sun et al., 2024), but also dowels or screw are used; Configuration 1.2 - a T-shaped plate is placed inside a milling at the beam end, connected generally through dowels (Masaeli et al., 2020; Jayasekara and Foster, 2023; Li et al., 2024), but also bolts are used (Salem and Petrycki, 2016; Zhang et al., 2023); it is connected to the column generally through bolts (Salem and Petrycki, 2016; Masaeli et al., 2020; Jayasekara and Foster, 2023; Zhang et al., 2023; Li et al., 2024), but also screws are used (Madland et al., 2024); Configuration 1.3 - two rectangular steel plates are placed at the sides of the beam end and of the column, they are connected through bolts (Salem et al., 2016); Configuration 1.4 - a U-shaped plate is placed at the timber beam end, connected through bolts (Zhang et al., 2023) or dowels (Jayasekara and Foster, 2023; Li et al., 2024); it is connected to the column through-bolts. Among Type 2 joints, two types of configurations can be distinguished: Configuration 2.1 - a double timber column and a central beam are generally connected to each other by screws, nails (Johanides et al., 2021), bolts (Beltran, 2016) or dowels (Polastri, 2010) in a circular arrangement; Configuration 2.2 - a double timber beam and a central column are connected to each other by bolts in a rectangular arrangement (Wang et al., 2021). Among Type 3 joints, two types of configurations can be distinguished: Configuration 3.1 - two steel L-shaped profiles made of aluminum (Kasal et al., 2010) or steel (Kang et al., 2022) are placed at the top and bottom of the beam end, connected to both the beam and the column with screws (Kasal et al., 2010) or bolts (Kang et al., 2022); Type 2 . Connection with circular or rectangular arrangement of fasteners; Type 3 . Connection with top and bottom plates or brackets and fasteners; Type 4 . Connection equipped with steel link; Type 5 . Post-tensioned connection with internal pre-stressed cable and dissipative devices. Among the Type 1 joints, four different configurations can be distinguished: