Accession Number : AD0622831

Title :   EXPERIMENTAL AND THEORETICAL PANEL FLUTTER STUDIES IN THE MACH NUMBER RANGE OF 1.0 TO 5.0,

Corporate Author : BOEING CO SEATTLE WASH AEROSPACE GROUP

Personal Author(s) : Dowell,E. H.

Report Date : AUG 1965

Pagination or Media Count : 25

Abstract : Three different theoretical analyses were carried out to better define the panel flutter boundary for simple panels. An analysis omitting the off-diagonal stiffness coupling terms and one that replaced the diagonal stiffness terms with eigenvalues of the complete stiffness matrix gave similar results. A method with the offdiagonal terms retained resulted in values of the flutter parameter that differed by approximately 30% from the two previously mentioned methods. This 30% difference in flutter dynamic pressure was for a/b = 4.0 and this difference approaches zero as a/b approaches zero. The change in natural frequency due to the inclusion of the off-diagonal stiffness terms had only a small effect on the flutter boundary. It was concluded that the change in the flutter boundary was brought about by the difference in panel natural mode shapes and thus increased the importance of accurately measuring the mode shapes. (Author)

Descriptors :   (*PANELS, FLUTTER), (*FLUTTER, PANELS), TRANSONIC FLOW, SUPERSONIC FLOW, HYPERSONIC FLOW, MATHEMATICAL ANALYSIS

Distribution Statement : APPROVED FOR PUBLIC RELEASE