Abstract
When an electromagnetic transducer is set in close proximity to a string for measuring the characteristics of vibration of the string, it has been analyzed that partial tones are non-harmonic because of attraction and that beats occur as a result of interference among the fundamental and the partial tones whose amplitudes are not so small. These problems can be formulated by approximating the attraction to the static component and stiffness component, and by using δ function to express the lumped force in the distributed system. The inherent elasticity of the string is accounted and the solution can be obtained by use of Laplace transform. The vibration characteristics can be analyzed from numerical calculation of the characteristic equation provided in the analysis process. Then, getting an approximated equation for the vibration frequencies, a method to correct the influence of the negative stiffness, is provided, and also a measuring system is constructed. The measured and corrected results are compared with the value obtained from Laser-doppler vibrometer, it can be identified that the corrected results have sufficient precision for practical use.
