Abstract: A calculation and test method for the natural frequency of a high-g micro accelerometer with complex structures is presented.A universal formula for natural frequency,which can significantly simplify the structural design process,is deduced and confirmed by experiment.A simplified analytical model is established to describe the accelerometer’s mechanical behavior and deduce the formula for the natural frequency.Finite element modeling is also conducted to evaluate the natural frequency of the micro-accelerometer and verify the formula.The results obtained from the analytical model and the finite element simulation show good agreement.Finally,a shock comparison method designed for acquiring the high frequency characteristics of the accelerometer is introduced to verify the formula by testing its actual natural frequency.

Key words: natural frequency, micro accelerometer, Rayleigh-Ritz formula