Research On Fatigue Fracture Behavior Of Generator Upper Bracket On Automobile

The engine is one of the main integrated components of the car,and its reliability is directly related to the performance of the car.Due to the complex assembly boundaries and operating conditions of the engine,the probability of failure of the engine is significantly higher than other components on the vehicle.As one of the main failure modes in electromechanical equipment,fracture failure will not only affect the efficiency of equipment use,but also cause casualties and large economic losses.At present,failure analysis is a complex interdisciplinary subject,and its related research methods and methods have been greatly developed.There is a vehicle engine that is researching a project that meets the emission standards of CHINA 6.the generator upper bracket broke three times during the endurance test of the engine,almost delaying the project.In this paper,the fracture failure problem is taken as the research object.The research method is the combination of theory and experiment.The mechanical performance,size,appearance and fracture analysis of the generator upper bracket are studied.At the same time,the engine accessory system to which the generator upper bracket belongs is calibrated.The analysis results show that the failure of the generator upper bracket is mainly due to the intermal welding stress generated by the welding process,the concentrated stress of the production and processing,and the plane deviation of the accessory system that do not meet the design requirements.According to the above analysis conclusions,an improved scheme for the upper bracket and engine accessory system of the generator is proposed.The theoretical calculation,simulation assembly interference inspection,simulation analysis of the modal and strength of the generator upper bracket by HyperMesh and ABAQUS,and production are proposed.The samples were tested for endurance.Finally,theoretical and engineering results show that the improved engine upper bracket and accessory system operates reliably and there are no more failures.By combining fracture failure analysis with engine modality research,this paper not only solves the actual engineering problems,but also the analysis process and the improvement verification process for reference by relevant engineers and researchers.