A two-DOF model-based input prediction for high-shock accelerometer calibration

Abstract

This article describes a two-degree-of-freedom (two-DOF) model-based input prediction method in the frequency domain for the comparison of high-shock acceleration calibration facilities. The current measurand for transferring the unit is the shock sensitivity as the relationship between the peak values of the accelerometer output quantity and the acceleration. The common transfer standards applied in shock calibration facilities in the range up to 100 km s−2 are piezoelectric-based transducers with a first resonance close to, or within, the spectrum of the exciting shock. This leads to the effect that the provided is, technically speaking, only valid for shocks of the same spectral composition, resulting in unpleasantly high uncertainties in high-shock measurements. This is thus not feasible if applied to shocks of differing spectral composition.A parametrized two-DOF model is capable of describing the transfer standard and allows the prediction of the applied input excitation with unprecedented accuracy. A method for the parameter identification and input prediction in the frequency domain and the results for two transfer standards are presented.