Identification Method Research of the Compressed Beam Elastic Buckling Load

Abstract

From the basic equations of dynamics, the precise expression of the relationship ,which was between the horizontal natural frequency and pressure load of the simply supported beam and the beam fixed at both ends with vertical pressures, was obtained. The approximate expression of the relationship, which was between the horizontal natural frequency and pressure load of the beam fixed at both ends with vertical pressures, derived from the variational methods. By comparing the precise numerical solution and the approximate solution of the beam fixed at both ends with vertical pressures, the conclusion of approximate linear relationship that was between the square of the natural frequency and axial force of the beam fixed at both ends with vertical pressures was got. Through theoretical and experimental comparing, the difference between the approximate solution and the accurate numerical solution was small, which could meet the requirements of accuracy on engineering. On this basis, as long as the natural frequencies of the structure at two load conditions are measured by experimental methods, elastic buckling load of the compressed beam can be identified.