Synchronous dynamic calibration of triaxial high-g accelerometers using a modified Hopkinson bar method: Theory, principle and experiment

Abstract

Because the inter-axis coupling effect and nonlinearity of triaxial high-g accelerometers (3-Axis-Gs) are significant under high-g and high-frequency loads, calibrating the sensitivity characteristics using a triaxial synchronous method is necessary but experimentally difficult. This study focused on the physics-based sensitivity model of 3-Axis-Gs, as well as the principle and experimental method of triaxial synchronous calibration. First, a sensitivity model of 3-Axis-Gs was established based on the physical source of cross-sensitivity. Then, a new triaxial synchronous calibration method was proposed using the modified Hopkinson pressure bar, which can simultaneously apply excitation accelerations with amplitudes greater than 100,000 g and frequencies greater than 50 kHz along the three axes of 3-Axis-Gs. Finally, a 3-Axis-G was calibrated using both triaxial synchronous and uniaxial calibration methods. Compared with uniaxial calibration, triaxial synchronous calibration can cover the entire test range, whose results can reflect the actual cross-sensitivity characteristics of 3-Axis-Gs in a three-dimensional loading environment.