
Accession Number : AD0668121
Title : STABILITY OF A THREELAYER ORTHOTROPIC PLATE IN A SUPERSONIC GAS FLOW,
Corporate Author : FOREIGN TECHNOLOGY DIV WRIGHTPATTERSON AFB OHIO
Personal Author(s) : Bagdasaryan,Zh. E.
Report Date : 29 AUG 1967
Pagination or Media Count : 18
Abstract : The report attempts to solve the problem of nonlinear flutter of threelayer rectangular plates, streamlined by a supersonic gas stream with a zero angle of attack. The layers are symmetrical w.r. to the neutral plane and the materials obey a generalized Hook's law. Normal displacements were assumed to be comparable with the thickness of the plate. A system nonlinear differential equations was given together with the expression for a transverse load, and boundary conditions. An approximate solution was assumed to be trigonometric and, on substitution, the original equations were shown to reduce to a nonlinear system of two equations in dimensionless variables, for the case of onesided streamlining with different stream velocities. The periodic solution near the critical value was sought by the method of successive approximations and the amplitude and frequency of established flutter vibrations were found by the BubnovGalerkin method. The amplitude of second approximation was also obtained. Two possible cases were discussed and a numerical example was given. The conclusions reached were that critical flutter velocity found by the above method is significantly smaller than that found from the classical theory, and that the difference between two values increases with the value of h1/a, where h1 is thickness of the plate and a is length of the plate.
Descriptors : (*SUPERSONIC AIRFOILS, FLUTTER), STABILITY, SUPERSONIC CHARACTERISTICS, GAS FLOW, RECTANGULAR BODIES, ANGLE OF ATTACK, THICKNESS, DIFFERENTIAL EQUATIONS, USSR
Subject Categories : Aerodynamics
Aircraft
Fluid Mechanics
Distribution Statement : APPROVED FOR PUBLIC RELEASE