Material Substitution Design Of Mg Motorbike Framework And Its Service Analysis

Energy conservation and performance improvement have become an inevitable trend in today's automobile industry. Therefore, it is of great importance to reduce the weight of vehicles. As a core structural component, the weight of motorcycle framework can be significantly reduced by using lightweight materials to improve fuel economy and reduce air pollution.This research is based on the scientific and technological project of Chongqing"The industrial technology development and application of magnesium alloy on motorcycle wheels and framework". In cooperation with the Yu-An Group, the steel framework of XGJ150-23 cross-country motorcycle was replaced by Mg alloy framework. The design and application development of Mg framework were tentatively conducted. The research has contributed to the application of Mg alloy for motorcycle framework.According to the principles of the structure design of motorcycle framework and the assembling requirements of the XGJ150-23 cross-country motorcycle, the structure of Mg alloy framework was finally designed in this thesis.Based on the products of Mg alloy and the technical specification of production and development, the 3D model of Mg alloy framework was completed, and the simplified mechanical model was established. The stress, strain and the modal of Mg alloy framework on three service conditions were analyzed. In the end, the structure of Mg alloy framework was optimized in accordance with the results and the requirements of molding process.Four main conclusions of the thesis are as follows:â‘ The 3D model was designed in accordance with the assembling and overall dimension requirements of XGJ150-23 cross-county motorcycle.â‘¡The mechanical service model of Mg alloy framework was established on three service conditions, and the strength and stiffness of the Mg alloy framework were analyzed based on safety requirements. The results have shown that the maximum service stress of the Mg alloy framework is less than 25 MPa and the stiffness of the Mg alloy framework meets the service requirements.â‘¢The natural mode of the Mg alloy framework was analyzed by finite element method. The results have shown that the minimum natural frequency of Mg alloy framework is 168 HZ, and it is lower than the dynamic excitation frequency of the normal service motorcycle. This will not cause the mechanical resonance of the Mg alloy framework in motorcycle service conditions.â‘£The structure of the Mg alloy framework was optimized on the basis of the comprehensive performance analysis and the framework process quality requirements. The weight of optimized framework is approximately 2.9 kg, which is 10 kg lighter than the primary steel framework.