## 1 Introduction  
With the continuous growth of people's demand for electricity, the necessity of developing long-distance, high-capacity, and trans-regional power transportation is increasing, and the construction environment of overhead transmission lines is complicated. The construction of new transmission lines across farmland, valleys, railroads, highways, and in-transit lines is also growing significantly yearly [1, 2, 3, 4, 5]. At the same time, laying new transmission lines usually presents problems, such as intersecting with ground lines or crossing people's work areas. To prevent falling objects from causing injuries to pedestrians or vehicles, it is necessary to build crossing frames in advance on both sides of the crossing and then carry out sealing net protection [6, 7, 8, 9, 10]. Overhead transmission lines are built in the sealing network structure across the road, railroad, highway, or other in-transit lines; their primary role is preventing the occurrence of broken line accidents and effectively intercepting falling broken lines to ensure that in-transit line regular operation follows, to ensure that the construction of the line is standard, and also to protect in-transit line regular operation [11, 12]. However, the traditional sealing net structure has the disadvantages of a long construction period, high cost, and ample floor space, and it will bring serious safety hazards to workers at height. Therefore, in recent years, the electric power industry has begun to study structures with a high degree of automation, low cost, and compact occupation. The new crawler-type net sealing machine comprises a lifting boom, a telescopic boom, a top protection net, etc. The boom adopts a nested truss structure, which can complete the net sealing operation with a span of 80 m and a height of 20 m. The net sealer's boom is a large-span space truss structure, a typical wind-sensitive structure with mechanical characteristics such as large deformation and high node stress; scholars at home and abroad have researched similar structures for these characteristics. [PERSON] [13] conducted a wind fatigue analysis on the Dong Ting Lake truss suspension bridge using pulsating wind in Yueyang City, Hunan province. Finally, he concluded that the boom's fatigue is most unfavorable when the wind's angle of attack is \(-3^{\circ}\) and that the tower on the leeward side is the critical point of fatigue damage. However, he did not give measures to improve fatigue strength, optimization, etc. [PERSON] [14] studied the dynamic response of wind load on the sealing structure under different spans, wind speeds, and additional diagonal cables and finally suggested mitigating the wind deflections. However, although the effects of various factors on the sealing structure were considered comprehensively, optimization and enhancement have not yet been conducted at the most unfavorable locations of the sealing structure. [PERSON] [15] introduced a new type of transmission structure (TC-PTS) suitable for mountainous terrain, established a finite element model, and performed wind fatigue analysis. The results showed that the intrinsic frequency and displacement timescales calculated for this transmission structure were highly accurate and efficient, and the most unfavorable wind angle of \(90^{\circ}\) was obtained for the TC-PTS. [PERSON] [16] proposed an analytical framework for efficiently assessing the fatigue reliability of typical large-span steel truss suspension bridges under random wind loads. The dynamic stress response of the bridge at critical locations was obtained by finite element analysis, which was sensitive to loading at one-quarter of the top and bottom chords of the main trusses. Still, ultimately, no one was given a way to reduce the sensitivity at this location.