Identification of Flexural Rigidity and Tension of the One-Dimensional Structure by Measuring Eigenvalues in Higher Order

In this paper, a new vibration method to estimate the tension T and the flexural rigidity EI of the one-dimensional beam is proposed. In this method periodic relation between the natural frequencies and the mode number is analytically derived from the frequency equation of lateral vibration in the beam, clamped at both ends with tension T.T and EI are estimated using least squares for the plural natural frequencies and modal numbers. As the result of numerical simulation of this method T and EI are estimated accurately in case of clamped and simply supported boundary condition at both sides of the beam. In case of unknown boundary condition the precision of T and EI is calculated quantitatively. Experiments using steel rods were achieved to verify the present method. Experiments boundary condition is between clamped and simply supported, and there is a good accuracy between the precision of experiments and the precision of numerical simulation.