# Accession Number:

## AD0722447

# Title:

## The Effect of Second Order Elastic Terms in Supersonic Panel Flutter of Finite Cylindrical Shells,

# Descriptive Note:

# Corporate Author:

## CALIFORNIA UNIV BERKELEY DIV OF AERONAUTICAL SCIENCES

# Personal Author(s):

# Report Date:

## 1970-12-01

# Pagination or Media Count:

## 27.0

# Abstract:

An analysis for the flutter boundary of a finite isotropic cylindrical shell under no static stress in a supersonic free stream is carried out at Mach numbers from 3-10. The effect of second order terms in the elastic equilibrium equation, which was not considered by Li 1967, is examined in detail. The aerodynamic load is computed following the same approximation usedby Li 1967, and the elastic displacement of the shell is resolved into a linear combination of sine functions to satisfy the clamped boundary condition at one end and simply supported conditions at the other end. This homogeneous system is solved by Galerkins method. Then the resultant matrix is transformed into a convenient form, having the same characteristic equation, and expressed in triangular form by means of QR-transformations. The required eigenvalues are the diagonal elements of the transformed matrix. The flutter boundary is defined as the curve where the imaginary part of the eigenvalue becomes negative. It is found that the effect of the second order terms is small. Author

# Descriptors:

# Subject Categories:

- Aerodynamics
- Fluid Mechanics