PSI - Issue 59

Mykhailo Hud et al. / Procedia Structural Integrity 59 (2024) 687–691 Mykhailo Hud et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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1. Introduction Donnell's nonlinear shallow shell theory is used to investigate the response-frequency relationship near a resonance frequency, the occurrence of travelling wave response and the presence of internal resonances for simply supported circular cylindrical shells by Amabili et al (2000). In this paper, the dynamic behaviour of functionally graded cylindrical shells of medium thickness is investigated. The material properties of the functionally graded cylindrical shell are graded in two directions (radial and axial) and are assumed to follow a power law distribution by Bahadori et al (2015). The paper describes a damping device that is based on shape memory alloy. The device comprises two wires made of pseudoelastic NiTi alloy that are preliminarily stretched and two compressed springs that ensure the wires' tension. The system's reliability and damping properties are provided by the compressed springs. Additionally, the preliminary compressed springs allow for alternating loads and the restoration of the device to its original position after the external load is removed (Iasnii (2020)). The investigation into the natural linear oscillations was conducted using the finite element method (FEM), with contributions from Yasniy et al. (2020), Pellicano (2007), and Pradyumna and Bandyopadhyay (2008). For the geometric modeling employed the finite element method (FEM) was utilized by Yasniy et al. (2011). The aim of this paper is to determine the frequencies and periods of natural oscillations by modelling the behaviour of a wooden frame under dynamic loading using local amplification. 2. Modelling The Lira software package and the Finite Element Method (FEM) were used to create the model of the timber framed manufacturing plant. Lira features a user-friendly interface, speed and the ability to import design schemas from other BIM tools. The columns are 20x20 cm and the beams are 20x20 cm. The wood of the C22 class with the appropriate physical and mechanical properties is used. The columns are fixed to the foundation with a rigid connection to the beams with a hinge. The height of the building at the top of the beam is 3 m. For the reinforcement of the columns, steel angles of 10 x 10 cm and 0.8 cm thick were chosen. Angle steel S235. The mechanical properties of S235 steel were used to model the following: Young's modulus E = 2.1  10 5 MPa; Poisson's ratio  = 0,3; ρ= 7,8 . 10 4 N/m 3 . The finite element model is shown in Figure 1. a b

Fig. 1. Framework model: a) finite element; b) 3D model.

3. Results and discussion As a result of the modelling, the natural oscillation frequencies of the unreinforced (Table 1) and reinforced with steel corners of the wooden frame columns (Table 2) were obtained.