Numerical analysis of a beam with and without viscoelastic treatment subject to cyclic loading in the time domain

Resumo

Its well-known that, the use of viscoelastic materials has been one efficient strategy to minimize fatigue
in structures. They have the characteristic of absorbing part of the vibratory energy of mechanical systems and
dissipating it in the heat form. Thus, the lower the vibrations produced, the lower the cyclic stresses and
consequently, the longer the beam supports the loading, increasing its fatigue life. Thus, in the context of fatigue
analysis, this work aims to analyze two scenarios: (1) the estimation of the fatigue life of an untreated beam made
of 1020 steel subjected to cyclic loadings; (2) the analysis of a beam treatment with passive constraining
viscoelastic layers. For this, the analysis of the results is performed in the time domain using the finite element

method. For the viscoelastic structure, a new fractional derivative model (FDM) is used to describe the time-
domain behavior of the viscoelastic part. For the fatigue analysis, the Rainflow method is used herein, based on

the stress-strain behavior of the material. Using this method, it was possible to determine the accumulated damage
by the Palmgren-Miner technique and, consequently, the fatigue life of the beam with and without viscoelastic
damping.