【作者】 丁睿；

【导师】 倪俊芳；

【作者基本信息】 苏州大学 ， 机械设计制造（专业学位）， 2023， 硕士

【摘要】 电连接器作为传递信号、电能的一种基础机电元件,对设备中各单元之间及系统之间的连接与分离起到至关重要作用。只要设备或系统当中某一个电连接器失效,整个设备或系统将会瘫痪。随着电动新能源汽车行业逐步形成了完整的产业链,电连接器的应用也变得广泛、数量可观,且在新能源汽车中电连接器多为电力传输型电连接器。相较于美欧等发达国家,我国电连接器的整体技术基础比较落后,失效率比国外同类产品高,因此对其研究意义重大。在新能源汽车中,电力传输型电连接器在使用当中,温度、电流和振动是导致电连接器性能退化的三大主要物理场,会造成接触表面的损伤和变形,导致接触件基体和其它结构的物理松弛等机械性能的变化。温度与电流是不可避免相互影响的两种物理场,温度与振动也是相互之间会产生一定影响的两种物理场。振动在汽车行驶时无处不在,外部机械振动会导致插头与插座在接触点间形成微小磨损,接触电阻突然增大。温度对电连接器性能影响主要表现在热力变形和对表面氧化速率的影响,而电流场的影响主要表现为电源的通断电、电压和电流的不稳定等。我国对电连接器研究集中于各大研究院以及大学,如中国航天技术研究院、北京邮电大学、浙江大学等等。研究内容则主要包括可靠性分析及实验、失效模式及机理研究、加速寿命实验等方面。然而国内外电连接器研究主要是针对信号传输型电连接器可靠性问题进行单物理场或双物理场研究,缺少对电力传输型电连接器的研究,理论研究缺少接触电阻准确描述模型,同时缺少单物理场和多物理场耦合情况下接触性能变化规律的研究。针对以上问题,将对REB型电连接器进行基于电连接器工作场景所受多场耦合下接触电阻理论、ANSYS与COMSOL仿真与正交试验研究,并对多物理场下电连接器仿真结果、理论结果与试验结果相互比对,以此验证接触电阻变化规律。本文研究内容如下:(1)基于电接触理论及各物理场下电连接器失效机理,得到电连接器各物理场下接触电阻退化模型;基于多物理场下耦合失效机理得到多物理场接触电阻退化模型。(2)建立REB型电连接器三维模型并进行简化,在ANSYS、COMSOL仿真软件中对其各边界条件进行设置;对退化模型中各未知量进行仿真并代入退化模型中得到接触电阻变化规律;对接触电阻变化情况进行仿真分析并与退化模型进行对比,验证单、多物理场下接触电阻退化模型准确性,两者对比结果准确率高。(3)对REB型电连接器进行单物理场实验,并对接触电阻进行实时监测,与仿真结果进行对比以进行验证;对多物理场情况下各因素建立正交实验表,对各组实验结果进行极差分析,判断影响因素优先级,对各组实验结果进行对比,分析各物理场变化对电连接器接触电阻变化规律的影响;对多物理场下正交实验结果与仿真结果对比以进行验证,两者对比结果准确率高。(4)基于接触电阻退化模型,通过多元随机过程对电连接器使用寿命进行预测。针对电连接器在使用过程中各物理场的连续与离散变化对现实使用情况进行模拟,结合多元Wiener过程与多元Gamma过程进行电连接器寿命预测。通过对电连接器失效机理与接触电阻基本理论进行分析,并在此基础上对多物理场耦合下电连接器接触性能进行建模,通过ANSYS、COMSOL进行仿真分析与正交实验,验证退化模型的准确性,并在此基础上对电连接器使用寿命进行预测,得到在给定条件下电连接器使用寿命约为5473个小时。更多还原

【Abstract】 As a basic electromechanical component for transmitting signals and electric energy,electrical connectors play a vital role in the connection and separation between units and systems in the equipment.As long as one of the electrical connectors of the equipment or system fails,the whole equipment or new system will be paralyzed.With the gradual formation of a complete industrial chain in the electric new energy vehicle industry,the application of electrical connectors has become extensive and considerable,and most of the electrical connectors in the new energy vehicles are electric transmission electrical connectors.Compared with developed countries such as the United States and Europe,the overall technical basis of electrical connectors in China is relatively backward,and the failure rate is higher than that of similar foreign products,so it is of great significance to study them.In new energy vehicles,during the use of electric power transmission electrical connectors,temperature,current,and vibration are the three main physical fields that cause degradation in the performance of electrical connectors,which can cause damage and deformation of the contact surface,leading to changes in mechanical properties such as physical relaxation of the contact substrate and other structures.Temperature and current are two physical fields that inevitably interact with each other,and temperature and vibration are also two physical fields that can have a certain impact on each other.Vibration is ubiquitous during vehicle driving,and external mechanical vibration can cause slight wear between the plug and socket at the contact points,resulting in a sudden increase in contact resistance.The impact of temperature on the performance of electrical connectors is mainly manifested in thermal deformation and the impact on surface oxidation rate,while the impact of current field is mainly manifested in the power supply on and off,voltage and current instability.The research on electrical connectors in China is concentrated in various research institutes and universities,such as the China Academy of Aerospace Technology,Beijing University of Posts and Telecommunications,Zhejiang University,and so on.The research content mainly includes reliability analysis and experiment,failure mode and mechanism research,accelerated life test,and other aspects.However,the research on electrical connectors at home and abroad mainly focuses on the reliability of signal transmission electrical connectors using single or dual physical fields.There is a lack of research on power transmission electrical connectors,and theoretical research lacks an accurate description model of contact resistance.At the same time,there is a lack of research on the variation of contact performance under the coupling of single and multiple physical fields.In view of the above problems,the contact resistance theory,ANSYS and COMSOL simulation and orthogonal test research will be carried out for the REB electrical connector based on the multi-field coupling of the electrical connector working scene,and the simulation results,theoretical results and test results of the electrical connector under the multi-physical field will be compared with each other to verify the change rule of the contact resistance.The contents of this paper are as follows:(1)Based on the electrical contact theory and the failure mechanism of the electrical connector in each physical field,the contact resistance degradation model of the electrical connector in each physical field is obtained;Based on the coupling failure mechanism of multi-physics field,the contact resistance degradation model of multi-physics field is obtained.(2)The three-dimensional model of REB electrical connector is established and simplified,and its boundary conditions are set in ANSYS and COMSOL simulation software;The unknown variables in the degradation model are simulated and substituted into the degradation model to obtain the change law of contact resistance;The change of contact resistance is simulated and compared with the degradation model to verify the accuracy of contact resistance degradation model under single and multiple physical fields,the results show high accuracy of comparison between both sides.(3)The single physical field experiment of REB electrical connector is carried out,and the contact resistance is monitored in real time,and compared with the simulation results to verify;An orthogonal experiment table is established for each factor in the case of multiple physical fields,and the range of the experimental results of each group is analyzed,the priority of the influencing factors is judged,the experimental results of each group are compared,and the influence of each physical field change on the contact resistance of electrical connectors is analyzed;The orthogonal experimental results and simulation results under multi-physical fields are compared to verify,the results show high accuracy of comparison between both sides.(4)Based on the contact resistance degradation model,the service life of electrical connectors is predicted by multivariate random process.Simulate the actual use of electrical connectors according to the continuous and discrete changes of physical fields in the process of use,and predict the life of electrical connectors by combining the multivariate Wiener process and multivariate gamma process.Based on the analysis of the failure mechanism of electrical connectors and the basic theory of contact resistance,the contact performance of electrical connectors under multiphysical field coupling is modeled,and the accuracy of the degradation model is verified through simulation analysis and orthogonal experiments by ANSYS and COMSOL.On this basis,the service life of electrical connectors is predicted,and the service life of electrical connectors is about 5473 hours under given conditions.更多还原