Page 25 - 2019

Ph.D.
(Engineering & Technology)
PARAMETRIC ANALYSIS OF ACTIVE VIBRATION CONTROL OF SMART
STRUCTURE USING ACTIVE CONSTRAINED LAYER DAMPING

Ph.D. Scholar : Mevada Jigneshkumar Rameshbhai
Research Supervisor : Dr. J. M. Prajapati

Regi. No.: 11146051005
Abstract :
Mechanical vibration control is really a challenging job for engineers nowadays.
Structures, especially subjected to vibration due to inherent unbalance or faulty design,
prone to vibrate; and sometimes fails in their performance. Controlling the vibration of
such structures require careful design of various parameters, which are affecting their
performance in their working environment.

Among many strategies for controlling the vibration and stability, active control of
structures, which is based on external power empowered by feedback mechanism from a
controller of system and proportional to sensor signal from vibrating system, is applied to
control the system vibration. Vibration control is one of the prominent factors, especially
in light weight structures in space technology. These structures, due to their low mass
and thinness, frequently lose the stability under environmental disturbances - a thermal
or an external load. In present study, a smart beam in cantilever configuration have been
modeled using numerical method.

Nowadays, piezo-electric and passive materials like viscoelastic materials have shown
combined advantage of hybrid damping (active constrained layer damping (ACLD)) and
with different parametric variations in them have shown remarkable property for control
authority. This research work presents a mathematical modeling and details of
parametric variations in smart structure, when structures are subjected to surrounding
temperature variations. Mathematical modeling is obtained using energy methods to
demonstrate the utility for further structure design. Finite element model has been
implemented using MATLAB software to analyse its effect of various parameters.
Parameters like percentage coverage of viscoelastic, piezo-electric material patches and
the shape of patches on damping characteristics have been demonstrated. A FEM model
has been validated with available experimental work. Different environmental
temperatures as thermal loads have been considered and their effect on damping ratio is
investigated. It has been observed that with different parameters, the performance of
active damping varies widely based on different settings. The performance of active
constrained layer treated beam have improved base on the particular coverage of
piezoelectric and viscoelastic layer and its thickness.

06