ASA 124th Meeting New Orleans 1992 October

4pSA7. Nonlinear vibration and radiation from a panel-stringer structure near a supersonic jet.

L. Maestrello

NASA-Langley Res. Ctr., M.S. 463, Hampton, VA 23665-5225

The experiment was undertaken to enhance understanding of nonlinear response and radiation involving random convective loading. Results presented show broadband nonlinearity of the vibration and acoustic radiation from a panel-stringer structure excited by a supersonic jet near field. The transmitted pressure field radiated from the structure is nonlinear, showing period doubling as well as chaotic behavior, and similarly for the strain response of the panel vibration. The radiation field also contains shocks and the formation of harmonics whose amplitude relative to that of the fundamental increases with distance. These results support the view that transient chaotic responses of the panels occur randomly.