CAE (Computer-Aided Engineering) technology has become a cornerstone of the development of computers, with several methods of numerical simulation such as FEM (Finite Element Method), MBD (Multi-Body Dynamic method), and topology optimisation used in production. Once original designs are developed, virtual experiments may also be conducted via CAE methods. These present some advantages including high efficiency, an improved product quality, and a reduction in the cost of product development [
1]. CAD (Computer-Aided Design) gives people a first impression before production, MBD allows for understanding how things may work before they really can, FEM carries out simulations more precisely, and topological optimisation provides a better solution. Homogenisation and artificial materials are mostly used in topology [
2]. Shape optimisation is a method of detailed design focused on modifying boundaries to achieve a solution [
3]. Size optimisation requires preliminary stiff and stress analyses and confirms the structure based on safety and lifetime rules [
4]. In 2007, Xiao et al. used both topological and shape optimisation methods to optimise the suspension bracket and the original design of the installation of the final design. The quality of the object reduced by 12% [
5]. In 2008, Huang et al., based on 28 working conditions from a general company, carried out a stress analysis with regard to the suspension bracket, applied the weighted flexibility as the objective function, took the minimum stress, considered modal frequency and volume ratio as constraints, and conducted a multi-working condition topology optimisation [
6]. In 2008, the suspension bracket was designed by the topological optimisation method and the structure topology optimisation was carried out using the smallest target function by Lv et al. After optimisation, the distribution of stress becomes more reasonable and the weight decreases by 9.4% [
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8]. In 2010, after a topological optimisation of the engine mounting bracket, a rationality analysis of material turnovers was carried out, and the test workload was dramatically reduced by the fem simulation of the fatigue test by Sue et al. In 2011, Wu et al., based on linear theory, calculated the ultimate load to withstand the stent by finite element software and confirmed its validity by a test of road durability [
9]. With regard to the optimal design of a stent, in 2011 Yang et al. found that the method of topological optimisation reduces the concentration of stress of the stent and improves the fatigue durability of the bracket [
10]. In 2012, the method of size optimisation was used by Liao et al. to optimise the bracket under such a working condition. As a result, the quality of the optimised stent increased by 37% [
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In this paper, we explore the power train of a pure electric vehicle by suspension bearings and provide a multi-body dynamic model by electric driving force assembly. To develop the condition of the electric vehicle characteristic, we calculate the situation of limit load. Thus, finite element modelling analysis and topology optimisation of the power train shell are conducted. The original fracture problem of the shell is solved by applying the optimised support. Some computer applications are used in the study, including ADAMS, ANSYS, and PRO/E, and the simulation results were found to be valid by a real vehicle experiment. The paper made a great contribution to solving the motor end cover mount bracket fracture engineering problems that have dogged this industry for a long time. In addition, the motor end cover was also improved via a topology optimisation, and its efficiency and performance have significantly improved since the optimisation.