Buckling Analysis of The Roof Structure at Venice Airport

Bistable structures exhibit multiple stable equilibrium configurations separated by unstable states, leading to nonlinear phenomena such as snap-through instability. These mechanisms are increasingly relevant in modern engineering applications, including morphing structures, adaptive systems, and energy-efficient mechanical devices. This thesis investigates the nonlinear behavior of bistable structural systems through analytical modeling, numerical methods, and dynamic analysis. The work is partly motivated by engineering experience gained during an internship at OneWorks, where a buckling analysis of the roof structure of the Venice Airport terminal was performed. This study highlighted the importance of geometric nonlinearities in large spatial structures and showed how structural geometry and loading conditions influence stability. Inspired by the roof-like structural configuration encountered in that analysis, the von Mises truss is adopted as a simplified canonical model to study bistable structural behavior. Despite its simplicity, this model captures the essential nonlinear mechanisms responsible for snap-through instability and provides a convenient framework for investigating the interaction between geometry, stiffness, and loading. The nonlinear static response of the system is derived analytically and investigated using several numerical solution techniques, including the Newton–Raphson method, the Arc-Length method, and the Modified Generalized Displacement Control Method (MGDCM). The dynamic behavior of the system is analyzed through its free response under different initial conditions. Stability analysis, phase portraits, and basin-of-attraction diagrams characterize the nonlinear dynamics and identify conditions leading to snap-through transitions. The results show that simplified nonlinear models capture complex bistable behavior and provide insight into nonlinear structural phenomena relevant to adaptive and bistable engineering systems.