Vibrations are oscillatory movements that occur in various physical systems. They can be categorized based on multiple criteria, including source, frequency, amplitude, propagation, spatial dimensions, and damping characteristics.

Source-Based Vibrations

  • Mechanical Vibrations: Caused by mechanical forces or moving parts.
  • Electromagnetic Vibrations: Result from electric or magnetic fields.
  • Acoustic Vibrations: Produced by sound waves.
  • Thermal Vibrations: Occur due to molecular motion in response to heat.

Frequency-Based Vibrations

  • Low-Frequency Vibrations (< 20 Hz): Includes seismic waves and structural movements.
  • Mid-Frequency Vibrations (20 Hz – 2 kHz): Typically found in machinery and industrial equipment.
  • High-Frequency Vibrations (> 2 kHz): Includes ultrasonic vibrations used in medical imaging and cleaning.

Amplitude-Based Vibrations

  • Large-Amplitude Vibrations: Visible or easily perceptible to human senses.
  • Small-Amplitude Vibrations: Often microscopic and imperceptible without instrumentation.

Propagation-Based Vibrations

  • Longitudinal Vibrations: Particle motion is parallel to wave propagation (e.g., sound waves).
  • Transverse Vibrations: Particle motion is perpendicular to wave propagation (e.g., light waves).
  • Surface Vibrations: Occur at the boundary of two media (e.g., seismic surface waves).

Spatial Dimension-Based Vibrations

  • One-Dimensional Vibrations: Confined to a single axis.
  • Two-Dimensional Vibrations: Oscillations occur within a plane.
  • Three-Dimensional Vibrations: Movements occur in all spatial directions.

Damping-Based Vibrations

  • Undamped Vibrations: Amplitude remains constant due to no energy loss.
  • Underdamped Vibrations: Amplitude decreases gradually over time.
  • Overdamped Vibrations: Amplitude decreases rapidly with minimal oscillations.
  • Critically Damped Vibrations: System returns to equilibrium in the shortest time without oscillation.

These classifications provide a framework for understanding and analyzing vibrations encountered in engineering, physics, and environmental sciences.