冲击波超压测试系统二次仪表频域特性

从二次仪表对冲击波的峰值、持续时间和比冲量3个主要参数的影响出发，首先构建了冲击波信号用以分析冲击波信号特性；搭建了适配器等效电路，对适配器的低频特性进行了实验研究；在MATLAB平台上构建了5种常用滤波器模型，模拟了不同类型滤波器和不同截止频率下测试系统的输出。模拟和实验结果表明:适配器的低频特性影响冲击波信号的持续时间和比冲量；在5种滤波器中贝塞尔滤波器最适合冲击波测试系统；滤波器截止频率对冲击波超压峰值影响明显；小型试验对测试系统的带宽要求高。

Frequency domain characteristic of secondary instrument in the shock overpressure measurement system

The frequency domain characteristics of measurement system are determined by transducer and secondary instrument, and the former one has been widely studied. It is shown that peak value, positive phase duration and impulse are affected by secondary instrument. The ideal shock wave signal was constructed for its frequency characteristic analysis. The low frequency characteristic of adapter was also experimentally investigated. Five different filters were modeled, and their output under different cutoff frequencies was simulated with the ideal shock wave as input signal. The simulation and experimental results are summarized as follows: The low frequency characteristic of adapter has the influence to positive phase duration and impulse; Bessel filter is the best one for shock wave measurement system of the five filters; The peak value of shock wave is obviously affected by the filters cutoff frequency; And the shock wave signal with short positive phase duration needs higher system bandwidth.