Project start: 1.10.2025.

The increasing demand for safe, energy-efficient, and cost-effective load-bearing frame structures necessitates a detailed examination, particularly regarding stability. Since such structures often contain slender beams with thin-walled cross-sections, their response to loading is more complex, with an increased tendency toward buckling and loss of stability. Although Euler-Bernoulli numerical models provide good results for slender beams, in laminated structures with rigid or semi-rigid joints, neglecting shear deformations can lead to significant errors in stability assessment. Therefore, accurately determining the stability limit state is crucial.

This research builds upon the applicant's previous work, focusing on the influence of shear deformations on the stability of thin-walled laminated frame structures. Interestingly, in laminated thin-walled cross-sections, certain interaction effects cannot be modeled without a theory that accounts for shear deformations. Laminated beams will be analyzed in four groups:

1. Symmetric and balanced laminates
2. Symmetric and unbalanced laminates
3. Asymmetric and balanced laminates
4. Asymmetric and unbalanced laminates

In the last three groups, certain interaction effects cannot be modeled without considering shear deformations, which can significantly affect the load-bearing capacity limit state. Since beam models for laminates in groups 2–4 are poorly represented in the literature, the applicant's beam model will be compared with shell models simulated in NX Nastran, Abaqus, or Ansys. Eigenvalue analyses and nonlinear stability analyses of loaded structures will be conducted based on the Updated Lagrangian formulation. Ultimately, this research is expected to result in the publication of several papers in this field, providing a theoretical and numerical foundation for the stability analysis of laminated frame structures, considering the influence of shear deformations.