Amplitude Decay
Mechanical energy dissipation that varies as a function of the vibration amplitude characterizes the behavior of micro-scale resonators operating at high drive levels. This non linear elastic damping occurs when the strain in the material exceeds the linear elastic limit, causing the damping coefficient to change dynamically. The result is a shift in the resonant frequency and a distortion of the classic symmetric resonance curve.
Dissipation Source
High stress levels activate microscopic defect motion and thermoelastic processes that deviate from linear predictions. Under these conditions, the non linear elastic damping introduces higher-order terms into the equations of motion, leading to amplitude-dependent losses. Designers must model these effects to predict how the sensor will behave when subjected to sudden shock or large accelerations.
Measurement Impact
Characterizing the sensor involves measuring the resonance curve at progressively higher actuation powers. As the drive increases, the non linear elastic damping causes the peak amplitude to saturate sooner than expected under linear theory. Metrologists detect this behavior by tracking the asymmetry in the frequency sweep and calculating the effective quality factor at different drive amplitudes.
This calibration ensures that the sensor signal processing can correct for the non-linear response during high-dynamic events.
Operational Boundary
The non-linear effects become negligible when the vibration amplitude is kept within the small-displacement regime. Operating the sensor below this threshold ensures that the damping remains constant and the frequency response is predictable.
