Dynamic analysis and uncertainty modeling of viscoelastic beam response to fluid stimulation: Insights into nonlinear effects and velocity uncertainties

This study investigates nonlinear vibrations in viscoelastic beams induced by external fluid flow. We introduce novel equations considering the Kelvin-Voigt viscoelastic model, geometric nonlinearity, and uncertainties in flow velocity for a more realistic analysis. A notable aspect of this work is the introduction of uncertainties in fluid flow velocity to enhance the realism of assumptions when estimating fluid forces acting on the structure. The nonlinear equation of motion acquired by using the second law of Newton and discretized by implementing the Galerkin technique. Then, the influence of fluid velocity and viscoelastic parameters on dynamic behavior and vibration behavior of the system are studied. Considering the uncertainties in fluid force, the statistical analysis using the Monte Carlo method reveals significant effects of uncertainties on system vibrations. Uncertainties in fluid velocity notably affect the acceleration amplitude, and show a noticeable increase in the lock-in area. This emphasizes the importance of considering fluid velocity uncertainty in designing such structures for optimal performance and structural integrity.