MODAL v7n4 - Experimental Modal Analysis of Miniature Objects by Optical Measurement Technique

ABSTRACT

In this paper, we analyze theoretically the use of correlation statistical properties in the random speckle field, in the non-contact recording of free-response information of vibrating objects, and in terms of time-domain signals collected simultaneously at multiple points, and we use system identification techniques in the frequency and time domains to identify the dynamic parameters. The bending vibration of a miniature cantilever beam and the torsional vibration of a miniature shaft with 3-degrees of freedom are measured. The dynamic property parameters identified are in good agreement with the theoretical values. By the same process, the lower-order natural frequencies and modes of the bending arm of a dental drill are measured and analyzed.