三轴随机振动条件下电连接器插孔簧片疲劳损伤研究

RESEARCH ON FATIGUE DAMAGE OF ELECTRICAL CONNECTOR JACK SPRINGS UNDER TRIAXIAL RANDOM VIBRATION CONDITIONS

针对电连接器在三轴随机振动环境下插孔簧片接触压力减小问题,建立了考虑电连接器装配关系和接触件连接情况的有限元模型,利用HyperMesh联合Ansys软件进行三轴随机振动有限元分析,得到不同振动应力水平下插孔簧片根部三轴向与三切向的应力功率谱密度,并基于最小畸变能原则合成其等效应力功率谱密度。使用非均匀离散傅里叶逆变换,根据等效应力功率谱密度计算得到插孔簧片根部的时域载荷历程,考虑插孔簧片根部预应力建立了应力均值与应力幅值的二维联合概率分布和当量载荷模型,并基于Miner累积损伤准则,给出了插孔簧片根部随振动时间和不同随机振动应力水平的疲劳累积损伤值。开展了三轴随机振动环境下电连接器恒定应力加速试验,结果表明,接触件插孔簧片接触压力减小是因为其开口直径增大,插孔簧片根部附近产生塑性变形,端面边缘材料出现不规则蠕动,且越靠近外侧蠕动趋势越强,由外向内逐渐减小。

To address the issue of reducing the contact pressure of jack spring in the triaxial random vibration environment of electrical connectors,a finite element model was built to reveal the assembly relation of electrical connector and connection of the contact components.The finite element analysis of triaxial random vibration was conducted by the combination of HyperMesh and Ansys software.The tri-axial and tri-tangential direction stress power spectral densities at the root of the jack spring were obtained under different vibration stress levels.Based on the principle of minimum distortion energy,the theoretical equivalent stress power spectral density was achieved.Accordingly,the inverse non-uniform discrete Fourier transform was applied to calculate the time-domain load history of the root of the jack spring.Considering the pre-stress imposed on the root of the jack spring,the two-dimensional joint probability distributions of mean stress and stress amplitude were established,and the equivalent load model was proposed.Based on the Miner cumulative damage criterion,the variations in the fatigue cumulative damage values for the root of the jack spring with vibration time and random vibration stress levels were plotted.The constant stress acceleration test of electrical connector was carried out in a tri-axial random vibration environment.The results demonstrate that the contact pressure of the jack spring is decreased due to its increased opening diameter.The plastic deformation occurs near the root of the jack spring,while the irregular creep appears at the edge of its root end.As the position approaching to the outside,the creep trend becomes stronger and is gradually enhanced from inside to outside.