Mechanical systems possess specific natural frequencies at which they prefer to vibrate, and each frequency corresponds to a distinct shape of deformation, known as a normal mode. Identifying these modes is critical in structural analysis to prevent resonance. If an external force, like a spinning motor, matches a normal mode frequency, the vibrations will amplify destructively.
The FEA shows the first normal mode is a twisting motion at 45 hertz, which is way too close to our operating speed.
Also heard as
- mode shape
- natural mode
Related terms
Flutter
A dangerous, self-feeding vibration in a flexible structure exposed to aerodynamic forces.
Damping
The dissipation of energy in a vibrating system to reduce the amplitude of oscillations over time.
Simple harmonic motion
A periodic oscillation where the restoring force is directly proportional to the displacement.