Low-speed electric vehicles (LSEV) are very popular in the less-developed area in China, and the industrial scale of LSEV is gradually expanding due to their great fit to the short-distance urban and rural travel and low purchase cost. However, the R&D strength and design investment of LSEV enterprises are uneven, and there are generally problems of unreasonable body structure and poor collision safety performance among LSEVs. In the transition period when the national mandatory standards are being developed, in order to make the LSEV enterprises complete the technology upgrade, this paper will build a FEM model based on a certain type of mass production vehicle and conduct collision simulation test to analyze the weak structure of the original structure and proposed a structural optimization.
After analyzing the development background and technical requirements of LSEV, this paper initially establishes the expected goals of LSEV frontal collision safety performance and builds the FEM model based on Hyperworks and LS-Dyna. By analyzing the test results, it is found that the energy-absorbing effect of the original frontal structure is insufficient, resulting in a high damage value of the driver when the collision occurs.
In order to overcome excessive acceleration, this paper optimizes the original bumper and the length of the energy-absorbing tubes in the frontal structure and adjusts some parameters of steel-pipe body frame. In order to reduce the amount of compression in the driver’s chest, a collapsible directional column will also be used. After optimization, the peak collision acceleration is reduced from the original 80 g to 67.1 g, and the time to fully absorb the collision energy is shortened from 65 ms to 40 ms, which significantly optimizes the safety performance of frontal collision.