Development of a Crustal Stress Measurement System Using Electronic Speckle Pattern Interferometry

Remarks on Residual Stress Measurement by Hole-Drilling and Electronic Speckle Pattern Interferometry

Hole drilling is the most widespread method for measuring residual stress. It is based on the principle that drilling a hole in the material causes a local stress relaxation; the initial residual stress can be calculated by measuring strain in correspondence with each drill depth. Recently optical techniques were introduced to measure strain; in this case, the accuracy of the final results depe...

Extended-range temporal electronic speckle pattern interferometry.

In recent years the availability of high-speed digital video cameras has motivated the study of electronic speckle pattern interferometry (ESPI) in the time domain. To this end a properly sampled temporal sequence of N-fringe patterns is used to analyze the temporal experiment. Samples of temporal speckle images must fulfill the Nyquist criteria over the time axis. When the transient phenomena ...

Vibrational power flow measurement in a beam using electronic speckle pattern interferometry

Phase Unwrapping of Electronic Speckle Pattern Interferometry Maps

This paper aims to provide an effective and distortion-free approach for the phase unwrapping of digital speckle pattern interferometry (ESPI) maps. ESPI is a very powerful measurement tool among industrial users. However, high percentages of noise are present in the experimental data obtained from the method and, therefore, most phase unwrapping algorithms fail to restore the correct phase fil...

Nondestructive Evaluation of Automobile Tires by Electronic Speckle Pattern Interferometry

Electronic speckle pattern interferometry (ESPI) was used for the evaluation of mechanical properties of automobile tires. The tire on wheel disc was fixed on the holder and its vibration was generated by loudspeaker. Vibrational field of the whole tire was visualized by ESPI and recorded into PC. Natural frequencies of various vibrational modes were measured and results were compared with thos...