Security and Usability Enhancing E-Service Marginalization for Digital Vulnerable Groups

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Author(s) Muchiri Michael Njoki | Franklin Wabwoba | Elyjoy Muthoni Micheni
Pages 542-554
Volume 4
Issue 12
Date December, 2015
Keywords Viscoelastic, Laminates, Damping, Natural Frequency
Abstract

The damping of structural components and materials is often a significantly overlooked criterion for good structural or system design. The lack of damping in structural components has led to numerous mechanical failures over a seemingly infinite multitude of structures. A method of reducing vibration in a system is to employ a dynamic vibration absorber. When a system is subjected to vibration of variable frequency or to broad band of random excitation, a number of resonances may be excited. It will be impracticable to have so many separate vibration absorber. To control and reduce vibration in such system, a visco-elastic material should be used as an active vibration damper. When laminated the damping characteristic especially for random excitation is improved. In this paper, Finite Difference Method (FDM) was used in analyzing the vibration of laminated visco-elastic beam. The results depicted shows that the damping reduces with increase in the coefficient of friction, while the dynamic deflection increases with the length of the laminated beam for different interfacial pressure. Also, a negative pressure gradient in a visco-elastic cantilever beam tends to increase the level of energy dissipation whereas an enhanced frequency ratio of the driving load tends to reduce the amount of energy dissipation that can be arranged via slip at the laminate interface. The findings confirm that each of these factors can independently be exploited to enhance the level of energy dissipation that can be arranged. It could therefore be stated that the laminates enhance the dissipation of vibration energy via slip damping of structures.

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