Extracting vibration characteristics of a guitar using finite element, modal analysis, and digital image correlation techniques

The sound quality generated by the guitar depends on the vibration characteristics (i.e. natural frequencies and mode shapes) of this instrument. Thus, it is of particular interest to the guitar manufactures to be able to extract global information about the characteristics of the guitar. Traditional sensors can only measure at discrete locations. However, digital image correlation (DIC) can measure full-filed data on the surface of the structure. In the current paper, a finite element (FE) model of a guitar was developed using quadratic shell, and solid elements. An eigensolution was performed on the FE model to extract its natural frequencies and mode shapes. In order to validate the numerical results, a modal impact hammer test was performed on the instrument. Furthermore, a measurement was performed on the guitar using the DIC technique. In this measurement, the guitar was placed in a free-free configuration and was excited using a broadband excitation generated by a sound source. The response of the ...