PSI - Issue 59

V. Iasnii et al. / Procedia Structural Integrity 59 (2024) 299–306

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V. Iasnii et al./ Structural Integrity Procedia 00 (2019) 000 – 000

shape memory alloys (SMAs), in localized critical areas (such as beam-to-column connections) of structures, exploiting the material's property to recover deformation. These unique characteristics can manifest at room temperature or upon heating, depending on the thermomechanical state of the material. The first is called pseudoelasticity, and the second is termed the shape memory effect (SME) (Reginald et al, 2004; Fang 2022). Passive control systems are considered more practical due to their simplicity of application and economical design (Javanmardi et al., 2022), compared to typical engineering structures made from traditional materials where plastic deformations may occur in connection zones or other structural elements with stress concentrations. In turn, structures equipped with damping devices hold a significant advantage, as the input energy is dissipated, thereby preventing damage to primary structural elements (Qiu et al., 2022; Yasniy et al., 2017). Despite considerable progress in developing and experimental testing these elements, technical challenges still exist (Fang 2022; Lai et al., 2020). According to the literature review, it has been shown that SMA elements have excellent damping capabilities. However, considering the complex designs of dampers and the combination of two types of materials, namely SMAs and conventional structural metals or alloys, there is a need to model the behavior of SMAs and devices of this type using the finite element method. This approach will allow for the alteration of structural parameters of such devices and swiftly obtain results regarding their behavior under static, cyclic, or other types of loads. 2. SMA damper 2.1. Basic configuration The paper examines a damping device, the structure of which is shown in Fig. 1. The device consists of a spring and four NiTi SMA wires (Iasnii et al., 2023).

Fig. 1. The overall view of the damping device structure.

2.2. FE Model The developed model of the damping device in ANSYS software (Divringi and Ozcan, 2009; ANSYS, 2009) is depicted in Fig. 2 and consists of a spring, SMA wire, and mass. For simplifying numerical computations and saving computational time, the four wires with a diameter of 1.5 mm were replaced by an equivalent area of 7.1 mm². The mechanical properties of the wire are presented in Table 1. The finite element model uses SOLID185, MASS21, and COMBIN14, comprising 15 147 nodes and 11 450 finite elements.

Table 1. Mechanical properties of the wire. Property

Value

Unit MPa MPa MPa MPa

420 465 210 120

σ SAS σ FAS σ SSA σ FSA