Aeroelastic behavior of a typical section with shape memory alloy springs: Modeling nonhomogeneous distribution of state variables

• Published in: Applied Mathematical Modelling 2017-12, Vol.52, p.404-416
• Main Authors: Sousa, Vagner Candido de, De Marqui Junior, Carlos, Elahinia, Mohammad
• Format: Article
• Language: English
• Subjects: Aeroelasticity; Alloys; Computer simulation; Cross-sections; Degrees of freedom; Effects; Flutter; Helical spring; Helical springs; Hysteresis; Martensitic transformations; Mathematical models; Shape memory alloy; Shape memory alloys; Shear strain; Shear stress; Smart material; Wind tunnel testing; Wind tunnels
• ISSN: 0307-904X; 1088-8691; 0307-904X
• DOI: 10.1016/j.apm.2017.07.056

•The aeroelastic behavior of a typical section with shape memory springs is investigated.•Hysteretic damping of preloaded superelastic shape memory springs is attractive.•The flutter and post-flutter behaviors of the typical section are enhanced.•Non-homogeneous distributions of properties in spring cross-section are considered.•Previously reported results are updated by an improved modeling approach. In this paper, a two-degree-of-freedom (namely, plunge and pitch) aeroelastic typical section with shape memory alloy helical springs in the pitch degree-of-freedom is modeled. A linear aerodynamic model is employed to predict the unsteady loads. The shape memory springs model is based on classical models modified by the von Mises pure shear assumption. Nonhomogeneous distributions of shear strain, shear stress and martensitic fraction in the wire cross-section are represented by axi-symmetric annular regions. The numerical predictions of the effects of pseudoelastic hysteresis of shape memory alloy springs on the aeroelastic behavior of the typical section when both the homogeneous and nonhomogeneous cross-sectional distributions are considered in the simulations are compared with experimental data obtained in wind tunnel tests. The nonhomogeneous assumption results in good agreement between numerical predictions and experiments. Both the numerical and experimental results show that the pseudoelastic hysteresis of SMAs can be employed as a passive alternative to modify the behavior of aeroelastic systems.