Dynamic Stability of a Sandwich Beam Subjected to Parametric Excitation

Mohanta, Laxmi (2006) Dynamic Stability of a Sandwich Beam Subjected to Parametric Excitation. MTech by Research thesis.

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Abstract

Vibration control of machines and structures incorporating viscoelastic materials in suitable arrangement is an important aspect of investigation. The use of viscoelastic layers constrained between elastic layers is known to be effective for damping of flexural vibrations of structures over a wide range of frequencies. The energy dissipated in these arrangements is due to shear deformation in the viscoelastic layers, which occurs due to flexural vibration of the structures. Multilayered cantilever sandwich beam like structures can be used in aircrafts and other applications such as robot arms for effective vibration control. These members may experience parametric instability when subjected to time dependant forces. The theory of dynamic stability of elastic systems deals with the study of vibrations induced by pulsating loads that are parametric with respect to certain forms of deformation The purpose of the present work is to investigate the dynamic stability of a three layered sym...

Item Type:	Thesis (MTech by Research)
Uncontrolled Keywords:	Vibration control, viscoelastic layers, cantilever sandwich beam
Subjects:	Engineering and Technology > Mechanical Engineering > Structural Analysis
Divisions:	Engineering and Technology > Department of Mechanical Engineering
ID Code:	142
Deposited By:	Shipra Awasthi
Deposited On:	07 May 2009 16:36
Last Modified:	07 May 2009 16:36
Related URLs:	Dspace
Supervisor(s):	Mohanty, S C

Dynamic Stability of Beams Under Parametric Excitatio

Mohanty, S C (2005) Dynamic Stability of Beams Under Parametric Excitation. PhD thesis.

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Abstract

The present investigation is an attempt to contribute towards the improved understanding of the dynamic stability of beams under parametric excitation. The dynamic stability of ordinary and sandwich beams subjected to longitudinal parametric excitation has been investigated theoretically and experiments have been carried out to validate some of the theoretical findings. The equations of motion have been derived using finite element method. For ordinary beams the instability regions have been established using Floquet’s theory and for sandwich beams modified Hsu’s method proposed by Saito and Otomi has been applied to determine the boundary frequencies of the instability regions. The dynamic stability of a Timoshenko beam with localised damage and having fixed-free, pinned-pinned, fixed-fixed and fixed-pinned boundary conditions has been investigated to study the effects of parameters such as extent of damage, position of damage, static load factor and boundary conditions on its dynamic...

Item Type:	Thesis (PhD)
Uncontrolled Keywords:	parametric excitation, Floquet’s theory, modified Hsu’s
Subjects:	Engineering and Technology > Mechanical Engineering > Structural Analysis
Divisions:	Engineering and Technology > Department of Mechanical Engineering
ID Code:	37
Deposited By:	Shipra Awasthi
Deposited On:	03 May 2009 17:28
Last Modified:	03 May 2009 17:28
Related URLs:	Dspace
Supervisor(s):	Kavi, N