Title

Experimental Study Of The Random Vibrations Of An Aircraft Structure Excited By Jet Noise

Date

1961

Index Abstract

Contrails and DTIC condensed

Photo Quality

Not Needed

Report Number

WADD TR 61-70

Creator

Clarkson, B. L.

Ford, R. D.

Corporate Author

University Of Southampton

Laboratory

Materials Central

Extent

36

Identifier

AD0258591

AD0258591

Access Rights

OTS

Distribution Classification

1

Contract

AF 61(052)-332

DoD Project

7351 - Metallic Materials

DoD Task

73521

DTIC Record Exists

Yes

Distribution Change Authority Correspondence

None

Abstract

Recordings have been made of the strains induced in a full scale rear fuselage test structure of the Caravelle airliner when one jet engine is running at maximum take-off thrust. The structure is a conventional sheet-stringer combination attached to pressed out frames.

The analysis has been concentrated on the strains in the centres of panels. Correlation measurements have indicated that the lower frequencies (up to 500 c.p.s.) are associated with overall vibration modes and have low strain amplitude. The larger panel strains occur at higher frequencies with the frames acting as boundaries. In these measurements the main resonance peak in each panel occurs at about 600-700 c.p.s. and has been identified with the fundamental stringer twisting mode (i.e., adjacent panels 180° out of phase). There are generally two smaller peaks in the 800-1000 c.p.s. range but the modes of vibration have not been completely identified due to lack of information.

An attempt has been made to calculate the panel resonant frequencies theoretically, assuming that the frames act as boundaries. Although this work appears promising it has not yet progressed far enough for any definite conclusions to be drawn from it.

Report Availability

Full text available

Date Issued

1961-03

Subject

Airframes

Jet Engine Noise

Vibration

Aircraft Panels

Fatigue (Mechanics)

Mathematical Analysis

Resonance

Stresses

Publisher

Wright-Patterson Air Force Base, OH : Wright Air Development Division, Air Research and Development Command, United States ir Force

Distribution Conflict

No

Provenance

IIT

Type

report

Format

1 online resource