Experimental and Mechanistic Study on the Calibration of High-g Accelerometers With Different Pulsewidth Excitations

Abstract

High-precision accelerometers are crucial in high-speed impact testing and precise detonation control of penetration fuzes. Calibration results of high-g accelerometers under narrow and wide pulsewidth impact conditions, however, show certain discrepancies, directly affecting the accelerometers’ measurement accuracy and application scenarios. This article focuses on studying the differences in the calibration of high-g accelerometer sensitivity using the narrow pulsewidth excitation method of the Hopkinson bar and the wide pulsewidth excitation method of the air cannon. The mechanisms behind these differences are quantitatively revealed, and the intrinsic relationship between the two calibration methods is established. First, calibration experiments were conducted on the same batch of accelerometers using both impact methods. Next, the linearity indices of the calibration results from both methods were calculated. Then, the differences in the calibration results of the two methods were analyzed and compared, followed by a detailed quantitative investigation of the underlying mechanisms behind these differences. Finally, an empirical formula was established through linear regression analysis to correlate the calibration results of the two excitation methods. The results indicate that there is indeed a difference in sensitivity between the two calibration methods. This difference is unrelated to the peak value of the excitation acceleration. It is, however, mainly influenced by the pulsewidth of the excitation acceleration and the amplitude-frequency characteristics of the accelerometer.