A methodology for an optimal design of physical parameters,positions,and viscoelastic materials of simple dynamic absorbers for passive vibration control

Dynamic vibration absorbers are simple mechanical devices that are attached to a structure aiming at reducing vibration levels. Designing such devices for vibration control of mechanical systems using viscoelastic materials results in low costs, easy construction, and higher efficacy due to their ability to dissipate vibration energy. In this context, the present study aims at developing a methodology for an optimal design of a set of viscoelastic dynamic absorbers considering their natural frequencies, the positions to attach them onto the structure to be controlled, and the viscoelastic materials as variables to be optimized for different working temperatures. The optimal configuration is obtained by applying a hybrid optimization technique, which uses genetic algorithms (considering continuous and discrete variables in the same design vector) aiming at approximating the global minimum point and, subsequently, a nonlinear programming method (simplex based on the Nelder–Mead method) to perform a local search. An example of dynamic absorber design to reduce vibration levels in a one-degree-of-freedom (DOF) system and on a steel plate (multiple-DOFs) is presented. The results show the efficacy of the methodology for passive control of vibrations acting on a broadband of frequencies and different temperatures.