| dc.description.abstract | Smart materials are very important because of their potential applications in the
biomedical, petroleum and aerospace industries. They can be used to build systems
and structures that self-monitor to function and adapt to new operating conditions.
In this study, we are mainly interested in developing a computational framework for
the analysis of plate structures comprised of composite or functionally graded materials
(FGM) with embedded or surface mounted piezoelectric sensors/actuators. These
systems are characterized by thermo-electro-mechanical coupling, and therefore their
understanding through theoretical models, numerical simulations, and physical experiments
is fundamental for the design of such systems. Thus, the objective of this
study was to perform a numerical study of smart material plate structures using
a refined plate theory that is both accurate and computationally economical. To
achieve this objective, an improved version of the Reddy third-order shear deformation
theory of plates was formulated and its finite element model was developed. The
theory and finite element model was evaluated in the context of static and dynamic
responses without and with actuators. In the static part, the performance of the
developed finite element model is compared with that of the existing models in determining
the displacement and stress fields for composite laminates and FGM plates
under mechanical and/or thermal loads. In the dynamic case, coupled and uncoupled electro-thermo-mechanical analysis were performed to see the difference in the evolution
of the mechanical, electrical and thermal fields with time. Finally, to test how
well the developed theory and finite element model simulates the smart structural
system, two different control strategies were employed: the negative velocity feedback
control and the Least Quadratic Regulator (LQR) control. It is found that the
refined plate theory provides results that are in good agreement with the those of the
3-D layerwise theory of Reddy. The present theory and finite element model enables
one to obtain very accurate response of most composite and FGM plate structures
with considerably less computational resources. | en |
