In-plane pulsed carrier speckle interferometry for structural surface intensity measurement

Experimental validation of structural intensity analytical and Finite Element calculations has traditionally relied on accelerometer and strain gauge point-wise measurements, although more recently laser vibrometry has been applied. Whole field measurements of structural intensity has been limited to out-of-plane component analysis using holographic interferometry, and is suitable only for plate and membrane studies. This paper describes a novel form of in-plane Electronic Speckle Interferometry. The interferometer has been developed specifically to assess the suitability of whole field speckle metrology for structural intensity analysis in three dimensional solids and objects, which require simultaneous in-plane velocity and strain measurements. A resonant beam is examined using the optical technique, with comparative data obtained from contact transducers.