Séminaire LTDS (comodal : présentiel & en ligne - ENTPE) : A beam-like model for dynamics and stability of thin pipes

Présenté par : Prof. Daniele ZULLI
Dept. Civil, Construction-Architectural and Environmental Eng., University of L'Aquila, Italy


En présentiel : ENTPE, Vaulx-en-Velin, Amphi F217 ("Amphi du haut) et en visioconférence
Lien Zoom : https://zoom.us/j/95809195770

Résumé au format pdf

A beam-like model is proposed to address nonlinear dynamic response of a thin pipe, under the action of a resonant transverse load. The mechanical model consists of a Timoshenko beam enriched with further kinematic and dynamic variables which, besides extension and bending, consistently describe local effects, related to ovalization and warping of the cross-section. The constitutive elastic law is obtained after an identification procedure from a three-dimensional companion continuum, suitably introduced. The nonlinear equations of motions are derived via virtual work, and internal resonance between the global and local modes is addressed by the multiple scale method, after a Galerkin projection of the equations on the first significant modes. The softening behavior induced by the local deformation remarkably affects the asymptotic solution, which turns out to be in good agreement with that provided by numerical integration. Effects of pre-stress on the pipe are analyzed as well, after deduction of the consistent geometrical stiffness and consequent evaluation of the critical loads.