A Numerical Method for Eigenvalue Buckling Analysis of Grid Structures

It was discussed and proved that the element selection in eigenvalue buckling analysis of grid structure should adopt multi-section beam element. The stability of the hinged compression rod and the hinged truss was analyzed, and the analytical solution was compared with the approximate solution. It was pointed out that the key to element selection lies in the appropriate shape function. The eigenvalue buckling analysis of the single grid structure and the grid considering the lower frame was carried out by using the rod element, the non-segmented beam element and the segmented beam element (multi-segment beam element). Among them, the beam element considered different shape functions. The research showed that the lowest-order buckling load factor was too large for the eigenvalue buckling analysis of the grid frame using rod elements. However, if the beam element using higher-order shape functions was not segmented, a more accurate buckling load factor could be obtained, but the buckling mode could not reflect the member buckling. Using beam elements and considering segmentation, a more accurate critical load could be obtained, and its buckling mode could reflect the member buckling.