| This dissertation deals with the development of viable numerical solution algorithms and computer programs for mode interactive structural instability problems, under static and dynamic loading conditions. The finite element based problem formulation takes into account the interaction between local and overall buckling modes, and considers postbuckling behavior of structures having arbitrary boundary conditions and cross-sectional shapes, with geometrical imperfections.; The solution is obtained by using two integrated numerical procedures, which combine the nonlinear postbuckling analysis procedure and a simplified method of mode interaction analysis. A thin plate finite element and a plane frame finite element are developed and utilized in this study.; In order to validate the present study, two computer programs are developed by employing both the implicit and explicit methods of direct time integration. The implicit computer code is developed especially for the efficient treatment of thin-walled structural members under static loading. On the other hand, the explicit computer code is developed to efficiently handle thin-walled frame structures under dynamic loading. Several illustrative numerical example problems are solved using these codes. The validity, accuracy, and efficiency of the present study are established by comparing the computer solutions with the available experimental data, as well as the results obtained from other numerical and analytical studies. Based on the current findings, several conclusions concerning mode interactive buckling behavior and dynamic response of thin-walled frame structures are presented and discussed. |
