Finite element analysis of the rotary micromechanical gyroscope vibrations
|Keywords||micro-electromechanical systems, micromechanical gyroscope, eigenfrequencies and mode shapes|
|Programs in use||ANSYS|
Natural oscillations of the rotary micro-mechanical hyroscope utilized in modern navigation systems for angle velocity measurements are analyzed.
Sensitive element (oscillator) of the rotary micro-mechanical hyroscope is presented at Fig. 1. Zone of oscillator fastening to the glass basement is marked with white. Oscillator is made of monocrystalline silicon. Its elastic properties is local coordinate system is described by three independent moduli. 3D FE model containing 3328 20-node elements (88416 DOF) was created based on solid model.
Effect of temperature-induced stresses on the spectrum of natural frequencies is analyzed. FE model created allows to take into consideration technological (manufacturing tolerance loss) and temperature factors. Fig. 4 illustrates relative displacement vector modulus Usum/R (R – radius of the silicon plate, R ~ 103 microns), originated due to welding of the silicon and glass parts and subsequent cooling till Т = 20°С.
First (torsional) natural mode shape of the rotor-type microgyroscope
Second (bending) natural mode shape of the rotor-type microgyroscope
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