Parametric stability analyses of composite reinforced structures

This study aims to enhance the accuracy and reliability of predicting dynamic instability in various structural systems. To achieve this, we will employ variable-fidelity finite one- and two-dimensional elements. These elements will be utilized to assess instability thresholds of different structural configurations under periodic excitations. The finite element formulations will be based on arbitrary kinematic models obtained through the Carrera Unified Formulation. By appropriately selecting the kinematic assumptions, we can automatically derive either equivalent-single layer, layer-wise, or component-wise approaches. We will adopt Taylor- and Lagrange-type expansions to derive the displacement field. Following Floquet’s theory, we will employ the methodology proposed to investigate instabilities, including those resulting from multi-mode couplings. Our focus will be on studying the response of stiffened composite structures to various multi-harmonic excitations and preload conditions. We will examine the effects of lamination sequence and stiffening strategy on stability thresholds. Additionally, we will utilize reduced-order models to decrease computational efforts. By incorporating these advanced modeling techniques, we aim to improve the accuracy and reliability of predicting dynamic instability for a broader range of structural configurations.