Evaluation of Structural Dynamic Modification by Viscoelastic Neutralizers based on Response Reanalysis Methods
Palavras-chave:
Response Reanalysis, Structural Modification, Vibration control, Viscoelastic material, Viscoelastic neutralizerResumo
Structural modifications can occur for several reasons, such as unsatisfactory product for the customer,
structural defects, updating of obsolete parts, generation of intense noise from the equipment to the operator, and
unwanted vibrations. When there is some prior knowledge of the dynamic characteristics of the mechanical sys-
tem of interest, particularly in association with the region where the changes will occur, a practical and convenient
approach is to analyze the effects of these changes using reanalysis techniques. These techniques aim to predict
the dynamic behavior of the system after implementing modifications, from a compact and specific set of data
related to the system and the modifications. The present work aims to investigate the use of two response reanal-
ysis techniques - in matrix formulation - to evaluate the effects of inserting viscoelastic dynamic neutralizers as
localized structural modifications. Viscoelastic neutralizers are considered in the context of future implementation
of vibration control on a cantilever steel beam. In modeling the neutralizers, concepts of generalized equivalent
parameters are used to maintain the same dimension in the system matrices before and after inserting the devices.
To validate the use of the employed techniques, their predictions are compared to the results obtained by an es-
tablished computational program dedicated to the optimal design of dynamic neutralizers in mechanical systems,
named LAVIBS-ND®. It is shown that the investigated techniques do not differ, as far as their predictions are con-
cerned, from the technique currently used in the above mentioned program, which is employed as a benchmark to
assess the accuracy of the evaluated methods. It is then concluded that the focused techniques are actually capable
of accurately predicting the effects of structural modifications by viscoelastic dynamic neutralizers for vibration
control purposes.
