Vibration Damping of Thin-Shell Deployable Structures Through Local Buckling

This study explores vibration damping induced by local buckling in ultra-thin composite shell structures under frequency-dependent loading. High periodic forces near a resonant frequency can trigger local instabilities, diminishing the shell’s ability to transfer loads and strains reducing it dynamic response. Understanding this behavior is essential for optimizing system design. Both experimental and numerical approaches are employed. Experimentally, two boundary conditions are analyzed. Sine sweep loadings are applied to a 500-mm-long Triangular Rollable and Collapsible (TRAC) longeron near its natural torsional frequency at varying amplitudes, with damping ratios determined via the Half-Power Bandwidth Method. Numerically, the structure is modeled using a refined one-dimensional beam finite element based on the Carrera Unified Formulation, with three-dimensional capabilities. Nonlinear dynamics are simulated with an implicit scheme using the Newmark method of the Hilbert-Hughes-Taylor type. Results highlight damping effects caused by local buckling in the flanges of the longeron, as evidenced by variations in damping ratios across the two setups. Simulations closely match experimental results, providing valuable guidance for structural optimization.