Confocal Laser Vibrometry

Identification of Bolted Joints through Laser Vibrometry

We present a new technique for identifying the dynamics of bolted joints. The technique relies on the comparison of the overall dynamics of the bolted structure to that of a similar but unbolted one. The di!erence in the dynamics of the two systems can be attributed solely to the joint; modelling this di!erence in the dynamics enables us to construct a non-parametric model for the joint dynamic...

Bayesian Spectrum Analysis for Laser Vibrometry Processing

Laser vibration sensing provides a sensitive non-contact means of measuring vibrations of objects. These measurements are used in industrial quality control and wear monitoring as well as the analysis of the vibrational characteristics of objects. In laser vibrometry, the surface motion is monitored by heterodyne laser Doppler velocimetry, and the received heterodyne signal is sampled to produc...

Stress determination of micromembranes using laser vibrometry

A laser vibrometry based dynamic technique for biaxial residual stress determination in micromembranes is reported. Layered, low pressure chemical vapor deposition (LPCVD) grown, rectangular shaped micromernbranes are ultrasonically excited. The resulting micrornembrane displacement, as a function of frequency and position, is recorded to yield resonance frequencies and associated vibrational m...

Laser vibrometry from a moving ground vehicle.

We investigated the fundamental limits to the performance of a laser vibrometer that is mounted on a moving ground vehicle. The noise floor of a moving laser vibrometer consists of speckle noise, shot noise, and platform vibrations. We showed that speckle noise can be reduced by increasing the laser spot size and that the noise floor is dominated by shot noise at high frequencies (typically gre...

Laser Vibrometry Across Sectors Laser Vibrometry Across Sectors Non-Contact Measurement of Structural Dynamics in Civil Engineering Application Notes