Eventos Anais de eventos
DINAME2019
DINAME2019
Experimental and numerical vibration analyses of tow-steered com- posite plates
Submission Author:
Daniel de Almeida Pereira , SP , Brazil
Co-Authors:
Domingos Rade, Thiago Guimaraes
Presenter: Daniel de Almeida Pereira
doi://10.26678/ABCM.DINAME2019.DIN2019-0200
Abstract
New materials have been providing more flexibility in designing of lightweight structures. Among these mate- rials, fiber reinforced composite materials have been attracting a great deal of attention. Hence, a deep understanding not only of static but also of the dynamic characteristics of composite structures is of primary concern. In particular, the understanding of the damping mechanisms is necessary for improved designs, despite the fact that modeling and characterization of dissipation effects are deemed difficult tasks. Previous studies show that carbon-fiber reinforced polymers (CFRP) can be designed in terms of damping characteristics by acting on its physical and geometric features. In recent years, advances in manufacturing processes have made it possible to consider non-conventional designs in order to improve the properties of composite materials. In particular, the development of automatic fiber placement (AFP) allows the realization of variable stiffness composite laminates (VSCL), among which tow-steered composites, in which continuous fibers follow curvilinear paths, are considered very promising. Therefore, the objective of this pa- per is to present an experimental and numerical assessment of the influence of fiber steering on the modal damping of CFRP plates for different fiber trajectories. The dynamic model is derived by using a semi-analytical approach based on the combination of the Classical Lamination Theory with the Rayleigh-Ritz (Assumed-Modes) approach. The modal damping factors are calculated using the Strain Energy Method, which is based on the ratio between the stored and the dissipated energies, giving the specific damping capacity (SDC) for each vibration mode. Preliminary results, which are to be complemented in the full version of the paper, have shown that, indeed, fiber steering can exert strong influence on the modal damping factors of composite plates, and the numerical prediction of natural frequencies and modal damping factors correlate quite well with the experimental counterparts.
Keywords
CFRP, damping, SDC, tow steering, variable stiffness composites, strain energy method
