基于真实铁路振动环境的车载印制电路板可靠性分析

Reliability analysis of vehicle-mounted printed circuit cards based on real railway vibration environment

以我国西北地区铁路运输环境真实振动数据为基础,利用不同频率、幅值与相位的谐波叠加方法生成随机振动信号。采用理论分析方法,建立谐波相位影响随机振动的功率谱密度、峭度和偏离度的数学模型,进而根据该模型,编制Matlab程序对真实非高斯振动环境的时域信号进行数字模拟。利用ANSYS软件建立车载印制电路板(PCB)的3D有限元模型,通过静力分析、模态分析验证有限元模型的正确性、合理性,同时根据结果对比,对有限元模型进行修正,保证获得较为准确的PCB有限元模型。最后,根据非高斯随机振动模拟结果和车载PCB有限元模型,分析PCB的响应,根据材料的S-N曲线、雨流计数法和Palmgren-Miner准则,通过FE-SAFE软件预测车载PCB在真实非高斯随机振动条件下的疲劳寿命。

Based on the real vibration data from the rail transport environment in Northwest China,using the superposition method of harmonic with different frequency,amplitude and phase to generate the random vibration signal,this paper establishes a mathematical model which the harmonic phase affects the random vibration power spectrum density,kurtosis and deviation with the theoretical analysis method,and writes the Matlab programs to simulate the real non-Gaussian vibration environment time-domain signal according to the model.By building the 3Dfinite meta-model of automotive printed circuit board（PCB）with the software ANSYS,it then uses the static analysis and modal analysis to verify the correctness and rationality,while comparing the results of modifying the finite element model to obtain a more accurate finite element model of the PCB.Finally,according to the simulation results of the non-Gaussian random vibration and the finite element model of the automotive PCB to analyze the PCB＇s response,based on the SN curve of materials,rain flow counting method and the Palmgren-Miner criterion,this paper can predict the automotive PCB fatigue life through the FE-SAFE software under real conditions of non-Gaussian random vibration.