随机振动下电连接器性能退化及磨屑迁移

Performance degradation and wear debris migration of electrical connectors under random vibrations

摘要:

为探究电连接器在运行过程中随机振动导致其接触件发生微动磨损,产生磨屑造成接触性能降低的问题,分别进行步进应力及恒定应力随机振动试验。采用电容层析技术对微动磨损过程中电连接器接触件间磨屑进行检测,研究振动周期、振动方向、振动量级和负载电流对磨屑堆积与分布的影响；对试验后的试品进行表面形貌及能谱分析,并引用分形维数研究磨屑分布均匀度,量化接触件表面的磨损程度。试验结果表明:振动周期、振动方向、振动量级对接触件间磨屑的产生与堆积具有正向累积效应；负载电流因发热与应力松弛的耦合作用,延缓了性能退化过程；轴向振动磨损最为严重；插针根部为严重磨损区域；电连接器在步进应力随机振动下的性能退化规律与恒定应力下相似,且步进应力下的磨屑特征值呈现出一定的阶跃变化特征；电连接器在微动磨损过程中接触表面形貌会发生显著变化；表面形貌及能谱分析结果与磨屑特征值及接触电阻变化规律相吻合。

Abstract:

To investigate the fretting wear of the contact parts of electrical connectors caused by random vibrations during operation, resulting in decreased contact performance due to wear debris, stepped stress and constant stress random vibration tests were conducted. Electrical capacitance tomography technology was used to detect the wear debris between the contact parts of the electrical connectors during fretting wear. The effects of vibration period, direction, magnitude, and load current on wear debris accumulation and distribution were studied. Surface morphology and energy spectrum analysis were conducted on the specimens after testing, and fractal dimension was used to study the uniformity of debris distribution, quantifying the extent of wear on the contact surfaces. Results of the tests show that vibration period, direction, and magnitude have a positive cumulative effect on the generation and accumulation of wear debris between contact parts. The coupling effect of load current, leading to heating and stress relaxation, delays the performance degradation process. Axial vibration causes the most severe wear, with the root of the pin being the area of severe wear. The degradation patterns of the electrical connectors under stepped stress random vibration are similar to those under constant stress, with wear debris characteristic values under stepped stress showing a certain step-change feature. Significant changes occur in contact surface morphology during fretting wear of the connectors. The results of surface morphology and spectrum analysis align with the characteristics of wear debris and the variation in contact resistance.