Accession Number : AD0752548

Title :   Bi-Normal Coordinates in Discrete Systems with Application to an Aircraft Shimmy Problem.

Descriptive Note : Technical rept.,

Corporate Author : AIR FORCE FLIGHT DYNAMICS LAB WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Rogers,Lynn C.

Report Date : JUN 1972

Pagination or Media Count : 262

Abstract : The use of bi-normal coordinate theory in the analysis of practical discrete systems provides the substantial benefits of conceptual value/physical insight, computational utility, and enhanced redesign capability. These benefits are explained and demonstrated in the present effort with attention to practical considerations. Section 1 extends the theory and presents the new material together with some previously available results in a coordinated manner. In particular, the nature of response in a single homogenous phasor mode is described in detail. Also, an expression for the derivative of an eigenvalue is developed and explained. Section 2 reports the analysis of an aircraft nosegear shimmy problem using bi-normal coordinate methods. Stability boundaries, mode shapes, and sensitivities to parameter changes are presented. Derivatives of eigenvalues are used in Section 3 to illustrate automated minimum weight design for a shimmy-free nosegear. Recommendations for further research are made. (Author)

Descriptors :   (*NOSE WHEELS, *VIBRATION), DAMPING, STABILITY, AIRCRAFT TIRES, EQUATIONS OF MOTION, MATRICES(MATHEMATICS), TORQUE, GRAPHICS, COMPUTER PROGRAMMING, NUMERICAL ANALYSIS, THESES

Subject Categories : Aircraft
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE