The Very Near Field II An introduction to Very Near Field Holography

Format:

Conference/Event

Author/Creator:

de Bree, H-E, author.

Conference Name:

SAE 2005 Noise and Vibration Conference and Exhibition (2005-05-16 : Grand Traverse, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2005

Summary:

In [1] is shown that very close (distance smaller than L/2Π) to a vibrating and flat structure with typical size L, the normal particle velocity and the (normal) structural velocity coincide. It is shown that with an acoustic particle velocity sensor the normal acoustic particle velocity close to the surface can be measured and that this velocity coincides with the surface velocity that is measured with a laser vibrometer or accelerometer.In [1] it is also shown that in the very near field (contrary to the behavior in the near field) the particle velocity level doesn't depend upon frequency. Furthermore, in the very near field, there is a linear relationship between the particle velocity as measured and the structural velocity to be measured.In this paper it is shown that the normal acoustic particle velocity appears to be a good representation of the structural velocity up to distances of L/2 (with L the size of the vibrating structure) and lateral movements of the structure are not measured by the lateral particle velocity. It is also shown that the lateral acoustic particle velocity is zero if the normal velocity is maximal.A simple holography method is presented based on the very near field concept

Notes:

Vendor supplied data

Publisher Number:

2005-01-2446

Access Restriction:

Restricted for use by site license