vibrometrie

Vibrometry, sometimes rendered as vibrométrie in French and vibrometrie in German, is the measurement of vibrations of objects over time. It characterizes vibration amplitude, frequency, velocity, and phase, and is used to study the dynamic behavior of structures and materials. The field covers both contact and non-contact methods and is important for design validation, testing, and nondestructive evaluation.

Common methods include contact sensors such as accelerometers and velocity sensors that are attached to the test object. Non-contact methods rely on optical techniques, notably laser Doppler vibrometry (LDV) and laser interferometry, which measure velocity or displacement by detecting Doppler shifts or phase changes in reflected laser light. Other approaches include electronic speckle pattern interferometry (ESPI) and holographic vibrometry, which enable full-field measurements of surface displacement or deformation.

Applications of vibrometry span modal analysis, structural health monitoring, and vibration testing of machinery and components. It is widely used in automotive and aerospace development, civil engineering, and the characterization of microelectromechanical systems (MEMS). LDV offers high-frequency measurement with a wide dynamic range and is suitable for delicate or rotating parts, while ESPI and holographic techniques provide full-field displacement data.

Key considerations include optical access, surface reflectivity, and alignment, as non-contact methods depend on a clear line of sight to the surface. Environmental conditions and calibration affect accuracy, and laser safety is a practical concern. Measurements are typically reported as velocity, displacement, or acceleration with phase information, enabling detailed dynamic characterization.