【作者】 侯捷；

【导师】 刘奕帆；

【作者基本信息】 内蒙古大学 ， 电子信息， 2023， 硕士

【摘要】 弹簧操动机构是断路器中的核心部件,在电力系统的安全控制方面起着举足轻重的作用,弹簧操动机构是否安全可靠直接关系到电力系统的效率。弹簧操动机构在运行过程中受力复杂,其强度、刚度和疲劳性能关乎着整体机构的安全性和可靠性,据统计在断路器操动机构所造成的故障中,由于机械故障原因造成的故障率在87%左右。因此,运用有限元方法合理分析弹簧操动机构关键部件的性能和疲劳寿命是十分必要的。本文以平高集团的一款断路器中的弹簧操动机构作为分析对象,通过对其工作原理的分析,采用有限元仿真手段对弹簧操动机构的三大过程进行研究,得出关键部件的运动特性以及局部应力分布,以及在冲击下的应力谱,并对关键部件的疲劳寿命进行了预测分析。本文根据企业提供的图纸,利用一款建模软件将弹簧操动机构整体三维模型进行建立,通过ANSYS中Workbench软件对此机构进行了静力学仿真分析,得到了该机构在最大弹簧力的作用下受到的局部危险点分布、应力应变情况等;同时研究了导致该机构出现拒合以及零件磨损不均匀的影响因素。为了得到关键部件在碰撞冲击前的速度以及载荷变化情况,通过多体动力学软件ADAMS对弹簧操动机构进行了三大关键过程运动特性仿真,通过与试验样机的试验数据和技术特征进行对比,验证了所建模型的准确性;并在此基础上得到关键部件的速度变化曲线以及载荷的时间变化曲线。然后同时运用ANSYS/LSDYNA对储能末期的碰撞冲击进行了数值计算,通过与试验测量结果对比验证了仿真结果的真实性,并得到关键部件的载荷谱。根据冲击疲劳的特点以及关键部件的失效形式,在参考常规疲劳寿命计算的方法上,结合关键部件材料的疲劳寿命参数对传统的局部应力应变法进行修正,得到了适用于弹簧操动机构关键部件的疲劳寿命预测模型,再结合Miner线性累积损伤法对链条销轴的冲击疲劳寿命进行了估计。更多还原

【Abstract】 Spring operating mechanism is the core component of circuit breaker,which plays an important role in the safety control of power system.The safety and reliability of spring operating mechanism is directly related to the efficiency of power system.The force of spring operating mechanism is complex in the process of operation,and its strength,stiffness and fatigue performance are related to the safety and reliability of the overall mechanism.According to statistics,the failure rate of the circuit breaker operating mechanism caused by mechanical failure is about 87%.Therefore,it is necessary to use finite element method to reasonably analyze the performance and fatigue life of key components of spring operating mechanism.In this paper,the spring operating mechanism of a circuit breaker of Ping Gao Group is taken as the analysis object.Through the analysis of its working principle,the finite element simulation method is used to study the three major processes of the spring operating mechanism,and the motion characteristics and local stress distribution of the key components,as well as the stress spectrum under the impact,and the fatigue life of the key components is predicted and analyzed.In this paper,according to the drawings provided by the enterprise,a modeling software is used to establish the whole three-dimensional model of the spring operating mechanism.The statics simulation analysis of the mechanism is carried out by the Workbench software in ANSYS,and the distribution of local dangerous points,stress and strain conditions of the mechanism under the action of the maximum spring force are obtained.At the same time,the influencing factors leading to the rejection of the mechanism and the uneven wear of the parts were studied.In order to obtain the velocity and load changes of key components before impact,the kinematic characteristics of three key processes of spring operating mechanism were simulated by ADAMS,a multi-body dynamics software.The accuracy of the model was verified by comparing with the test data and technical characteristics of the test prototype.On this basis,the velocity curve and load time curve of key components are obtained.Then,ANSYS/LSDYNA was used to calculate the impact at the end of energy storage.The authenticity of the simulation results was verified by comparing with the test results,and the load spectrum of key components was obtained.According to the characteristics of impact fatigue and the failure forms of key components,the traditional local stress strain method was modified by referring to the conventional fatigue life calculation method,combined with the fatigue life parameters of key components,and the fatigue life prediction model suitable for the key components was obtained.Combined with Miner’s linear cumulative damage method,the impact fatigue life of chain pin was estimated.更多还原