physics

In the mid-20th century, when Carleen Hutchins was at the height of her career, it was unusual enough for a woman to make violins. It was even more unusual for a violin maker to conduct hands-on acoustic research, harnessing technology so that modern hands might build instruments to rival the work of 17th- and 18-century masters.

But Mrs. Hutchins did something more unusual still. Working intently and noisily in her home in Montclair, N.J., she helped reimagine the idea of what a violin could be.

This article is quite technical and will only be interesting to a very selective audience. It is a general introduction into experimental modal analysis - a technique that is often used to analyse violins. This article is not specific to analysing instruments but all the techniques are similar and applicable to instruments. Coming from a mechanical engineering background I found it really interesting. It first appeared as part of the conference notes of CSI Reliability Week, Orlando, FL October, 1999.

Registered users can download the article in PDF format here.

ABSTRACT

Experimental modal analysis has grown steadily in popularity since the advent of the digital FFT spectrum analyzer in the early 1970’s. Today, impact testing (or bump testing) has become widespread as a fast and economical means of finding the modes of vibration of a machine or structure.

In this paper, we review all of the main topics associated with experimental modal analysis (or modal testing), including making FRF measurements with a FFT analyzer, modal excitation techniques, and modal parameter estimation from a set of FRFs (curve fitting).