Analysis And Design Of Structural Fatigue Reliability Of High-voltage Circuit Breaker Components

With the rapid development of China's economic construction,the application of construction machinery in social production has become more widespread.The working environment of the high-voltage circuit breaker spring operating mechanism is relatively harsh and the load is large.At work,there are impact loads with short acting time and strong force,and such impact loads may exist in one working cycle;fracture damage occurs in some areas with large stress,and with the continuous action of impact load,Cracks expand rapidly,causing damage to mechanical components and loss of service capacity in a short period of time.Carrying out fatigue reliability analysis and optimization,and exploring the fatigue analysis method of mechanical parts under impact load,it is of great significance to improve the safety of spring operating mechanism.In this paper,the high voltage circuit breaker under cyclic impact load is taken as the research object.Based on the reliability series model,the fatigue relieving life prediction of the weakest link interlocking raft structure in the spring operating mechanism under the impact load is selected.Structural response surface methodology for structural optimization.The specific research contents are as follows:Firstly,the research background is introduced and the research status of fatigue research is summarized.The research method of structural reliability is analyzed.The importance of fatigue life of S-N curve is analyzed and the types of S-N curves are introduced.How to obtain the appropriate S-N curve through correction is obtained.Method of interlocking tweezers fatigue analysis;The causes of the failure of the fracture parts of the interlocking tweezers are analyzed,and the fatigue life analysis method proposed in this paper is applied to the interlocking tweezers in the spring operating mechanism,and the existing optimization design scheme is summarized,and the appropriate method is selected for optimization.Stress analysis of interlocking tweezers and fatigue life analysis using finite element software;The life prediction method based on nonlinear cumulative damage and impact model combines the nonlinear damage Corten-Dolan model with the reliability mathematical impact model,and proposes a predictive fatigue life model for nonlinear fatigue damage,considering the fatigue limit.The fatigue damage caused by the load and the interaction between the loads.At the same time,compared with the existing fatigue life prediction models,the proposed method can be applied to the fatigue life prediction of structural members under impact load with higher accuracy.