Influence of Quasiperiodic Gravitational Modulation on Convective Instability of Liquid-Liquid Polymerization Front

The influence of quasiperiodic gravitational modulation on convective instability of polymerization front with liquid monomer and liquid polymer is studied. The model includes the heat equation, the concentration equation, and the Navier-Stokes equations under the Boussinesq approximation. The linear stability analysis of the problem is carried out and the interface problem is derived. Using numerical simulations, the convective instability threshold is determined and the boundary of the convective instability is obtained for different amplitudes and frequencies ratio

Using delayed damping to minimize transmitted vibrations

, it was shown that in a single degree of freedom system a fast nonlinear parametric damping enhances vibration isolation with respect to the case where the nonlinear damping is time-independent. The present work proposes additional enhancement of vibration isolation using delayed nonlinear damping. Attention is focused on assessing the contribution of a delayed nonlinear damping over a fast parametric damping in terms of minimizing transmissibility. The results show that a nonlinear damping with delay greatly improves vibration isolation

Galloping of Wind-excited Tower under External Excitation and Parametric Damping

Abstract This paper investigates the in luence of combined fast external excitation and parametric damping on the amplitude and the onset of galloping of a tower submitted to steady and unsteady wind low. A lumped single degree of freedom model is considered and the cases where the turbulent wind activates either external excitation, parametric one or both are studied. The methods of direct partition of motion and the multiple scales are used to drive the slow low near primary resonance. The in luence of the combined excitation on the galloping is examined. The results shown that not only the amplitude of galloping is in luenced, but also the onset of galloping

4th International Conference on Structural Nonlinear Dynamics and Diagnostics

This book presents a selection of contributions from the 4th International Conference on Structural Nonlinear Dynamics and Diagnostics, reflecting diverse aspects of nonlinear and complex dynamics. Fifteen chapters discuss the latest findings and applications in active research areas in nonlinear mechanics and physics. These includes the dynamics of ships with liquid sloshing interaction, dynamics of drops and bubbles, nonlinear drying processes, suppression of time-delayed induced vibrations, dynamics of robotic systems, chaos detection in rolling element, dynamics of a planetary gear system with faults, vibro-impact systems, complex fractional moments for nonlinear systems, oscillations under hysteretic conditions, as well as topics in nonlinear energy harvesting and control