## 1 Introduction  
Fatigue of the wires in an overhead conductor occurs within the couplings that restrict the conductor vibration from incurring a vortex-induced oscillation [1; 2; 3]. At present, most of the overhead conductors are made of steel-cored aluminum strands (ACSRs), and ACSR is widely used in power delivery systems around the world [4; 5]. An aeolian vibration is one of the causes of a refitting fatigue failure of a conductor. Such failures invariably occur in suspension clamps, dampers, and spacers [6; 7]. The northwest part of China has several areas with a strong wind, which significantly impacts the operation of transmission and transformation lines. According to statistics, from July 2015 to September 2016, 750 kV ultra-high voltage (UHV) transmission lines undertaking the task of power transmission from the west to the east in a strong wind areas suffered three strand breaks of the mid-phase jumper in succession, resulting in significant economic losses. Therefore, it is very important to study the stress and deformation distribution of the mid-phase jumper in terms of the movement under strong winds to provide guidance for the treatment measures. [PERSON] et al. [8] described a method based on outlier analysis and the wavelet transform for structural damage detection based on guided ultrasonic waves. Furthermore, this method was applied to the detection of notch-like defects in a seven-wire strand by using built-in magnetostrictive devices for ultrasound transduction. [PERSON] et al. [9] presented an innovative non-destructive experimental technique based on ultrasonic waves for a quantitative determination of the damage level in structural components. [PERSON] et al. [10] presented a systematic study using a magnetic non-destructive evaluation of corrosion attack in rope wires via Barkhausen noise emission. Because of the complexity of the scene, it is difficult to detect the damage of a six-splitting mid-phase jumper directly. Through the establishment of the finite element model six-splitting of a mid-phase jumper, the damage under wind load can be calculated. This paper presents an effective finite element modeling method for a large steel-cored aluminum strand when a main bending deformation occurs. Because of the interaction between strands, multi-layer strands have a variable bending stiffness. With the bending of the strands, they begin to gradually slide with respect to each other, resulting in a decrease in the bending stiffness. However, the structural model of the conductor studied here is larger and has a spatial bending form. Therefore, it is extremely difficult to establish a finite element model of a mid-phase jumper with equal proportions. Some scholars have proposed different modeling methods to study the mechanical response of steel strands during a bending deformation. [PERSON] and [PERSON] [11] idealized a strand as a series of concentric orthotropic cylinders, each of which is associated with a specific layer and its corresponding mechanical properties. The bending process of the wire was also considered. In addition, [PERSON] [12] studied the mechanical behavior of cables under an arbitrary combination of tension, torsion, and bending. The force model of the cables is universal. [PERSON] and [PERSON] [13] applied the love crank balance equation to each conductor and deduced a mechanical conductor model that can predict the stress of single twisted strands under axial, bending, and torsion loads. [PERSON] et al. [14] established a mechanical model of the conductor bending behavior under tension, although the model was significantly simplified. For example, the contact between adjacent cables of the same layer is neglected in the established model, and the contact line is used instead of the contact point of the superimposed layer. In addition, the cross-section of the twisted strand after bending is still planar. [PERSON] et al.