The Regions of Local and Global Instability of a Two-Member Slender System with Grack

In this paper the instability phenomenon of a column composed of two elements with different bending and compression stiffness's is presented. In the one of elements the crack modeled by means of rotational spring with linear characteristic is present. The boundary problem of an instability has been formulated on the basis of the minimum total potential energy principle. In this study only the results corresponding to the magnitude of bifurcation loading of the two element system are presented (rectilinear form of static equilibrium). These results were compared to the critical loading magnitude calculated for single element system (a system without crack). Finally the comparison of the bifurcation loading of a two element system to the single element one under consideration of different magnitudes of bending rigidity factor allows one to present the regions of local and global instability of the considered complex system.