Abstract The location of a vibration source within a machine is sometimes found to have a significant effect upon its radiated acoustic power. It is known that a simple reduction of vibration cannot always reduce the radiated acoustic power, so that treatments based on analysis of a structure’s vibration modes are not always effective. At the same time, radiation mode analysis is known to be a powerful tool for interpreting sound radiation since those modes are independent of a structure’s surface vibration. However, knowledge of the radiation modes alone cannot be used directly to understand the relationship between vibration source location and acoustic power radiation. In this paper, it is shown that the radiation mode concept can be extended to understand the relationship between acoustic power and driving force distribution by considering the product of the structure’s mobility matrix and the radiation modes: the resulting functions are here defined to be force radiation modes (frad-modes). An example is presented in which the acoustic power radiated by a simply-supported, baffled beam is reduced by using guidance provided by the structure’s force radiation modes. The results demonstrate that the force radiation modes can be used to guide the reduction of radiated acoustic power by changing the driving force location without the need to perform additional calculations or experiments.
[1]
Stephen P. Timoshenko,et al.
Vibration problems in engineering
,
1928
.
[2]
Hiroshi Katsuchi,et al.
Application of radiation modes to the problem of low-frequency noise from a highway bridge
,
2004
.
[3]
J. Stuart Bolton,et al.
Sound Radiation Modes of a Tire on a Reflecting Surface
,
2004
.
[4]
S. Elliott,et al.
Radiation modes and the active control of sound power
,
1993
.
[5]
Nobuo Tanaka,et al.
Active Control of the Structure-borne Sound. On the Relationship between the Control Effect of Vibration and the Sound.
,
1991
.
[6]
C. Fuller,et al.
Active control of far‐field sound radiated by a rectangular panel—A general analysis
,
1992
.
[7]
Jie Pan,et al.
Experimental study of different approaches for active control of sound transmission through double walls
,
1997
.