Oscillation Amplification
Physical phenomena occur when a mechanical system is subjected to an external force that oscillates at a frequency matching the natural frequency of the structure. Excessive structural resonance causes a dramatic increase in the amplitude of vibration within the system components. This condition can lead to mechanical failure or severe interference with sensitive instrumentation.
Modal Identification
Modal identification identifies the specific frequencies and mode shapes where the structure is most susceptible to excitation. During the design phase, engineers use finite element analysis to predict where structural resonance might occur. These models are then verified through experimental modal testing using shakers or impact hammers.
Sensor Interference
Sensor interference is a common consequence of structural resonance in the mounting hardware of accelerometers and gyroscopes. When resonance occurs near the operating bandwidth of the sensor, the resulting vibrations can saturate the electronics or create a substantial bias error. Damping materials and stiffening elements are used to move the resonant frequencies outside the range of interest.
High-precision measurements require that the natural frequencies of the sensor housing be well above the sampling frequency of the data acquisition system.
Fatigue Risk
Fatigue risk increases markedly when a system operates near its resonant points for extended periods. The repetitive stress cycles lead to the formation of micro-cracks in the material. Over time, these cracks grow and cause the structural integrity of the device to fail.
