Numerical analysis of optimum designed models of viscoelastic supports for rotating machines

Resumo

Viscoelastic supports (VES) are a simple solution for vibrations in rotating machinery with a low
associated cost. The objective of this work is to complement an optimal design methodology for VES, developed
by the GVIBS/UFPR group for rotating systems subject to unbalanced excitations, inserting a static stiffness in
parallel, whose purpose is to increase the load capacity of the device. The dynamic behavior of the rotating system
is represented through the finite element method. For the viscoelastic material, the fractional derivatives model of
four parameters is used, which allows considering the effect of temperature and excitation frequency. For the
optimal design, the concept of generalized equivalent parameters (GEP) is used, allowing to describe the equation
of motion of the composed system with VES, being able to obtain the response of the composed system in a space
or subspace of the primary system, efficiently from a computational time perspective. The primary system is
modeled considering a simple rotor and the support is introduced via GEP. Nonlinear techniques allow for optimal
design of the VES. Numerical simulations on rotors with known dynamic behavior allow showing the results of
the proposed methodology and the effectiveness of viscoelastic supports.