Identification Method Research of Elastic Buckling Load of the Compressed Beam at Two Ends Elastic Fixed

Abstract

From the basic equation of dynamics, the precise expression of the relationship, which is between the horizontal natural frequency and pressure load of the beam at two ends elastic fixed and subjecting to vertical pressures, is obtained. Its approximate expression derives from the variational method. By comparing the precise numerical solution and the approximate solution of the beam at two ends elastic fixed and subjecting to vertical pressures, the conclusion of approximate linear relationship that is between the square of the natural frequency and axial force of the beam at two ends elastic fixed and subjecting to vertical pressures is got. And the difference between the approximate solution and the accurate numerical solution is small, which can 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. So the no damage test method to identify the elastic buckling load of the structures is given.