## 1 Introduction
proposed a dynamic optimization trimming technique for enhancing the dynamic characteristics of gear transmissions, and this method combines the dynamic load factor [10]. [PERSON] et al. showed that the optimal gear trim has a significant effect on the dynamic characteristics, especially when differences in tooth shape and profile trim are considered [11]. [PERSON] et al. use theory, numerical simulation, and optimization design to analyze the effect of gear trimming on transmission noise of CRH380A EMU stock through finite element simulation and neural network and finally realize low noise design [12]. In [PERSON] et al. 's work, on the other hand, gears were reshaped by modifying the radius of the blade and the shape of the blade, which could improve the dynamic characteristics of the gears [13]. [PERSON] et al. used the envelope method to spread these into orthogonal arc-toothed gears; the outer diameter of the gears increased after trimming, and the phenomenon of the tooth apex becoming pointed was changed, which provided a basis for further study of the bias load characteristics [14]. [PERSON] et al. investigated the effect of gear tooth shaping on dynamic meshing contact stresses, and the results showed that shaping can significantly reduce the maximum contact stresses, which is expected to improve the life of gearboxes [15]. [PERSON] et al. researched the tooth bias loading problem of helical gears, using theoretical calculations and parameter optimization design methods to specify the optimal combination of trimming volume. The results show a 58.2% reduction in maximum tooth load, improving system performance [16]. [PERSON] et al. 's study introduced a method to solve the problem of gear transmission vibration, noise, and load unevenness, based on helical gear mesh contact analysis, established a multi-objective helical gear optimization trimming method, and achieved significant improvement [17].In addition, some studies have focused on the effect of trimming on the contact stresses, fatigue life, and transmission errors of gears [18; 19]. In addition, for the virtual prototype reconstruction method of trimmed gears, the scholars concerned used different software and techniques to build the trimmed gear model and compared them by optimizing the target parameters. This helps to validate the reduction in transfer error after trimming, as well as other performance improvements [20; 21; 22; 23; 24]. These studies provide the theoretical basis and practical application support for gear reshaping and provide a powerful tool for improving the performance of gear transmission systems. Today's literature focuses on simple tooth shapes and flank designs, such as schemes for trimming helical gears. However, in terms of virtual prototyping for reconstructing modified gears, the existing commercial software (e.g., Romax 18) only supports the reconstruction function of traditional helical gears and spur gears, but does not cover complex curved gears such as curved cylindrical gears, which limits its application scope to a certain extent. At the same time, the method of constructing a topologically modified gear model is relatively complex and difficult; thus, the topological modification method has some limitations in improving the performance of gears [25; 26]. In order to solve the above problems, this paper proposes a method using MATLAB and CREO that can quickly and accurately reconstruct the model of a modified arc-toothed cylindrical gear. This new approach has significant advantages over the existing methods. First, this method is applicable to a wider variety of gears and is no longer limited to traditional helical or spur gears. Secondly, this method greatly simplifies the design process of trimmed gears and improves the design efficiency. In addition, this paper also designs a comprehensive profile trimming scheme for tooth profiles combined with the radius of a curved-tooth line, which has a wider scope of application compared with the existing gear trimming software.