## 1 Introduction  
Most of the existing VIV-related research focuses on the structural responses, only a small part of them explain the meso-mechanism of VIV. Among them, some of the research objects are regular cross-section structures such as circular cylinders and square columns. [PERSON] et al. (2001) [1] discussed the mechanisms of VIV of inclined cables at a high reduced wind velocity region based on wind tunnel tests, and they found that the axial flow and the upper water rivulet had a controlling impact on the aerodynamic instability of inclined cables. [PERSON] et al. (2011) [2] proposed helical stake to suppress the VIV of cylinders, which is an effective measure leading to vortex dislocation and swirling flow rather than Karman-type vortex structures. [PERSON] et al. (2017) [3] investigated the effects of an internal nonlinear rotating dissipative element on the VIV of a circular cylinder and discovered that this element can affect the wake state and inhibit VIV. [PERSON] et al. (2018) [4] indicated that the leading-edge vortex is the main reason for the VIV of 5:1 rectangular cylinders, and that vortex structures impinged on the trailing edge caused the increase in VIV response. The decrease in the value and spanwise correlation of fluctuating lift, as well as the shift of aerodynamic damping from negative to positive, are two explanations for VIV suppression by helical wires, according to [PERSON] and [PERSON] (2020) [5]. [PERSON] (2020) [6] described the phenomenon of VIV for circular cylinders and explained the essential mechanisms of VIV based on the mathematical models. [PERSON] et al. (2016) [7] investigated the impact of the gap ratio on the cylinders' response in depth and discovered that for all of the computed gap ratios in the tandem configuration, the maximum amplitude is larger than that of a single cylinder. [PERSON] et al. (2020) [8] conducted experiments to compare the influence of two-dimensional and three-dimensional analysis on the calculation results of VIV responses of rectangular prisms, and discovered that the three-dimensional result is 1.2 times that of the two-dimensional, and that the three-dimensional modal effect and span-wise correlation are important factors. Over a wide range of decreased velocity, [PERSON] et al. (2021) [9] simulated VIV using linear springs as well as bistable springs with two distinct inter-well separations. Additionally, large oscillation amplitudes were discovered to correspond to lift force lock-in with the inherent frequency of the spring-mass system. In the other part, the mechanisms of VIV of bridges are mainly analyzed from the perspective of the vortex-induced force mathematical model or vibration suppression measures. [PERSON] et al. (2013) [10] proposed a mathematical model for box girders, and analyzed the mechanisms from the perspective of energy. [PERSON] and [PERSON] (2014) [11] developed an analytical model for VIV prediction of long-span bridges, and analyzed the important characteristics of locked-in phenomenon in detail, based on this model. Taking the Hong Kong-Zhuhai-Macao Bridge as the research object, [PERSON] et al. (2015) [12] discovered that continuous vortex-shedding near the crash barrier is the cause of the vertical VIV of this bridge, and that measuring the flow velocity near the crash barrier can suppress the vertical VIV of this bridge. [PERSON] and [PERSON] (2015) [13] proposed three effective VIV suppression measures and investigated the effects of different parameters of suppression measures on VIV performances. [PERSON] et al. (2018) [14] proposed a method to calculate the VIV performances of bridges and validated this method by calculating the VIV responses of a real bridge while considering the effects of spatial coherence and modal shape of vortex-induced forces. Based on particle image velocimetry (PIV) data, [PERSON] et al. (2018) [15] investigated the impact of grid plates on suppressing the VIV of twin-box girders and discussed the suitable range of grid plate settings. [PERSON] et al.