LOW FREQUENCY CABIN NOISE REDUCTION BASED ON THE INTRINSIC STRUCTURAL TUNING CONCEPT: THE THEORY AND THE EXPERIMENTAL RESULTS, PHASE 2
Low frequency cabin noise and sonically induced stresses in an aircraft fuselage may be reduced by intrinsic tuning of the various structural members such as the skin, stringers, and frames and then applying damping treatments on these members. The concept is also useful in identifying the key structural resonance mechanisms controlling the fuselage response to broadband random excitation and in developing suitable damping treatments for reducing the structural response in various frequency ranges. The mathematical proof of the concept and the results of some laboratory and field tests on a group of skin-stringer panels are described. In the so-called stiffness-controlled region, the noise transmission may actually be controlled by stiffener resonances, depending upon the relationship between the natural frequencies of the skin bay and the stiffeners. Therefore, cabin noise in the stiffness-controlled region may be effectively reduced by applying damping treatments on the stiffeners.
- Subm-Sponsored in Part by NASA.
Boeing Commercial Airplane CompanyP.O. Box 3707
Seattle, WA USA 98124
- SenGupta, G
- Publication Date: 1978-3
- Pagination: 104 p.
- TRT Terms: Aircraft; Aircraft cabins; Aircraft noise; Airframes; Damping (Physics); Dynamic loads; Fuselages; Jet propelled aircraft; Low frequency; Noise control; Protective coatings; Stiffness; Stringers; Structural analysis; Transmission loss; Vehicle compartments; Vibration; Wave motion
- Uncontrolled Terms: Dynamic response; Noise reduction; Structural stability
- Old TRIS Terms: Aircraft structures; Low frequencies; Skin structural member; Structural vibration
- Subject Areas: Aviation; Vehicles and Equipment;
- Accession Number: 00181679
- Record Type: Publication
- Source Agency: National Technical Information Service
- Report/Paper Numbers: NASA-CR-145262
- Contract Numbers: F33657-72-C-0829
- Files: TRIS
- Created Date: Oct 31 1979 12:00AM