Acoustic Fairing - An Application to Beam Reinforced Plates.
Abstract
The radiated sound from a beam reinforced plate excited by a point force is investigated. The point force is located on the reinforcing beam, simulating a standard method of supporting vibrating machinery by plate structures. The radiated pressure spectrum of excited reinforced plates was reduced by as much as 6 dB for moderately stiff beams. The radiated power generally decreased with increasing mass and stiffness of the reinforced beam, reaching by as much as 8 dB for excitation frequencies above the concidence frequency. The angle of coincidence usually increased with increasing mass and decreased with increasing stiffness of the reinforcing beams. The peak pressure at the coincidence angle could be reduced by as much as 12 dB by judicious choice of the geometry of a reinforcing beam, whose dimensions are generally dictated by structural design considerations. A method of adding other structural discontinuities to further reduce the radiated noise was also investigated. This is referred to as Acoustic Fairing in this thesis. The procedure thus employed consists of a pair of infinite line sprung masses, where one is located on each side of the reinforcing beam. The radiated sound from point excited reinforced plates with acoustic fairing was investigated and a parametric study was completed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 23, 1973
- Accession Number
- ADA040669
Entities
People
- Gau F. Lin
Organizations
- Pennsylvania State University