Title: Study of damping in layered and jointed welded structures

Authors: Bhagat Singh, B.K. Nanda

Addresses: Department of Mechanical Engineering, National Institute of Technology, Rourkela – 769008, Orissa, India. ' Department of Mechanical Engineering, National Institute of Technology, Rourkela – 769008, Orissa, India

Abstract: Vibration and noise reduction are crucial in maintaining high performance level and prolonging the useful life of machinery, automobiles, aerodynamic and spacecraft structures. It is observed that damping is caused by energy dissipation due to micro-slip along frictional interfaces. In this paper, a layered and jointed welded cantilever beam model has been considered for examining the vibration energy dissipation due to interfacial friction of jointed structures. Experiments are performed on mild steel specimens with a number of layers under different initial conditions of vibration to validate the theory developed. It is found that the interface pressure distribution characteristics, number of contacting layers, amplitude and frequency of vibration, length and thickness of specimen govern the damping capacity of jointed layered structures with welded joints. These results can be positively exploited in the design of machine tools, aircrafts, spacecrafts, satellites, automobiles and missile systems effectively to maximise their damping capacity.

Keywords: interface pressure; dynamic slip ratio; energy dissipation; number of layers; amplitude; frequency; length; thickness; logarithmic damping decrement; mechanical design; design engineering; vibration damping; noise reduction; cantilever beam models; welded structures; mild steel; damping capacity.

DOI: 10.1504/IJDE.2009.028650

International Journal of Design Engineering, 2009 Vol.2 No.2, pp.169 - 190

Published online: 21 Sep 2009 *

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