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Chapter 8

CHAPTER 8

FUTURE WORK

Work by Richardson [8] and colleagues at Cardiff University have presented evidence that modal effective weight may play a larger part in sound production and tonal balance than does the frequencies of the modes. Richardson suggested that “treble” and “bass” responses may lie in the manipulation of effective mass of the modes.

Future research, expanding work from this thesis, will follow the lead of Richardson and Elejabarrieta [8] [2], using finite element modeling in conjunction with real testing to build a much improved model to better simulate the real world guitar mechanisms, and delve further into the modal effective weight contribution to the dynamic system of the guitar.

Future FEM modeling shall include:

1. Concurrently create a real Martin D-28 guitar and a finite element model. Modal analysis, measurement of material properties and structural damping coefficients, and finite element model to test correlation would be performed to improve accuracy between actual article and FEM. Similar work has been performed on a classical guitar by Elejabarrieta [2].

2. Add temperature load in strings to add string tension until each resonates at a fundamental frequency equivalent to the standard guitar tunings.

3. Add fluid-solid elements to the model to simulate the surrounding air.

Once the aforementioned modeling and testing has been accomplished, the door for future research will be opened.

Future research shall include:

1. Normal modes analysis of the guitar that will allow further insight into the complex modal coupling effects of the top plate and back plate modes with the air cavity modes.

2. Expanded sensitivity analysis of the modal effective weight of top plate modes beyond the mode (0, 0).

3. Model various impulse functions into the string(s) to simulate the picking/plucking/strumming action by the player and analyze the transient response to various impulse techniques, parameter changes, structural designs, and degrees of modal coupling.

4. Evaluate the effect that modal effective weight change has on the loudness and frequency response function at various distances and directions from the guitar.

5. Analyze effects of increased weight at end of neck (i.e. heavier tuning machines) has on transient response and decay.

6. etc.

As outlined above, the potential directions for future research are numerous and more than feasible. Model correlation and increased model accuracy in future updates of the guitar will allow more direct results, opposed to the relative influence of various features and parameters as was realized in the presented work.