电动振动台随机振动试验有限元仿真

Random Vibration Test Simulation of an Electrodynamic Vibration Generator Based on Finite Element Methods

建立并修正了能反映某振动台、夹具以及试件整体动态特性的有限元模型,基于该模型进行了随机振动试验仿真研究,介绍了仿真方法。根据给定的加速度功率谱密度控制曲线,通过频率响应计算和随机响应计算对试件随机振动试验进行了仿真,获得了试件动态响应仿真结果。通过真实试验对仿真结果进行了验证,结果表明仿真控制曲线和试验控制曲线吻合很好,均在控制容差范围内;试件测点仿真结果和真实试验结果功率谱密度曲线比较一致,峰值频率相对误差为0.8%,仿真频段内各测点加速度响应均方根值相对误差在5%以内,自功率谱对应峰值最大相对误差约为22%。

The integral finite element model including a certain electrodynamic vibration generator, a clamp and a designed plate specimen was created and updated to describe its real dynamic properties. Based on the model, simulation of random vibration test was studied and the simulating method was introduced. According to the reference curves of acceleration power spectral density （ PSD ） , frequency response calculation and random response calculation were carried out to simulate the random vibration test. The simulating results of specimen＇s dynamic responses were obtained and compared with real random vibration test carried on the specimen. The comparisons show that the simulating control curve matches the testing control curve perfectly, both of which are within the bounds of admissible error. The acceleration PSD curves of corresponding comparative points are mostly coincident, that considering relative errors, the resonance frequency is about 0.8 percent, the whole root mean square of acceleration is within 5 percent and the maximal peak value of PSD is about 22 percent.