Multi-Frequency Broadband Vibration Mitigation of a Beam Under Tensile Load

The vibration characterization is directly associated with the system’s physical properties, such as mass, damping, and stiffness. For over a century, vibration resonator or dynamic absorber has been used for vibration control and mitigation in many sectors of engineering. A limitation of this device is that it acts as a notch filter, which is only effective over a narrow band of frequencies. Therefore, researchers have designed the call metamaterial, which in this case, targets the improvement of vibration attenuation and induces locally resonant bandgaps. This work investigates the broadband vibration mitigation of a beam under tensile load with periodically attached dynamic absorbers. The study uses the modal analysis approach, a simple formulation that only depends on the resonator target frequency and total mass ratio to investigate single and multiple-frequency bandgap formation. Metamaterial and rainbow metamaterial beam under tensile load are employed to widen the gap. In practical designs, a finite number of resonators is required for the open bandgap, and this ideal number is explored in the paper. Additionally, a tensiled beam (cable) virtual twin is built from a physical system to forecast its broadband vibration mitigation with the metamaterial approach. Numerical investigations are conducted regarding the effects of mass ratio and the ideal mass ratio on the open and on the gap convergence, as well as resonators in single and multiple arrangements inducing multiple gaps.

Modeling and animation of spring dynamic absorber

The investigation of the action of the spring dynamic absorber, as well as the calculation of the physical quantities of the constructed model and animation, was carried out using non-linear methods of the Runge-Kutta type. Using only three references to the right-hand side of the differential equation, a method of the third order of accuracy is constructed, as well as two-sided approximations of the second order of accuracy. An explicit estimate of the error at each point of integration is given.

Damping of vibration of the car suspension at resonance

A block diagram of the device has been developed, which is based on the principle of dynamic vibration absorption. The design of a dynamic absorber of car suspension vibrations is considered. A mathematical model of a car suspension with a dynamic vibration absorber and the results of its numerical simulation are presented. The analysis of the results obtained makes it possible to determine the optimal parameters of the device for a dynamic vibration absorber. Keywords: suspension, car, dynamic, damping, vibration, mathematical, model, analysis, parameters

A Novel Dynamic Absorber with Variable Frequency and Damping

Smoothness and discontinuous (SD) oscillator is a nonlinear oscillator with the variable frequency, whose frequency can be varied with the smoothing parameter. However, how to adjust the smoothing parameter has not been solved in the actual device. In this paper, the shape memory alloy (SMA) is introduced into the SD oscillator to form the SMA-SD oscillator to adjust the smoothing parameters. Combining the SMA-SD oscillator with MRF, a nonlinear dynamic vibration absorber (DVA) with variable frequency and damping is designed. The structure and control principle of the designed DVA is studied to achieve the two variable characteristics simultaneously by adjusting the current intensity. Numerical results on a two-degree-of-freedom coupled system show that the proposed DVA can adapt to different working conditions only by adjusting the current intensity.