激励脉冲宽度对加速度计冲击校准误差的影响

Effect of the Exciting Pulse Duration on the Error of the Shock Calibration for Accelerometers

加速度计准静态校准要求激励信号的频率与加速度计谐振频率相比足够低,以减小校准误差。通过加速度计数学模型建立了激励加速度脉冲宽度、加速度计谐振频率和校准误差之间的关系式;针对Hopkinson杆冲击校准装置,理论计算和实验结果表明,激励加速度脉冲宽度决定于应力脉冲前沿宽度,受应力波弥散影响,而与加速度计安装座长度无关。为选用和产生满足要求的激励脉冲信号提供了依据。

The frequency of the exciting signal should be lower enough than the resonant frequency of the accelerometer to reduce the error of the quasi - static calibration. The relation between the duration of the exciting acceleration pulse, the resonant frequency of the accelerometer and the calibration error was established through the mathematical model. In allusion to the calibration with Hopkinson bar, the theoretical calculation and the experiments show that the duration of the exciting acceleration pulse was determined by the rising-edge duration of the stress pulse, and influenced by the diffusion of thes tress wave, but is independent of the aceelerometer installing seat. The basis is provided for selection and generation the right exciting pulse.