Accession Number : AD0774845

Title :   Vibration Absorbers for Rocket Launchers Mounted on Helicopters: Analytical Analysis and Implementation Techniques.

Descriptive Note : Technical rept.,

Corporate Author : ARMY MISSILE COMMAND REDSTONE ARSENAL ALA GROUND EQUIPMENT AND MATERIALS DIRECTORATE

Personal Author(s) : Johnson,C. D.

Report Date : 02 JAN 1974

Pagination or Media Count : 87

Abstract : An analytical analysis of the dynamical behavior of the tuned-mass vibration absorber is presented, and the notion of optimum damping is introduced. Computational techniques for calculating optimum damping coefficients are developed and three representative numerical examples are solved. A nonlinear servo-control system is designed to achieve inflight automatic tuning of the tuned-mass absorber in the face of varying helicopter rotor speeds. The practical aspects of implementing active vibration absorbers are studied and some specific circuits and hardware schemes are proposed. A spring-linkage (parallelogram) mount, a cantilever-wing tuned-mass absorber, and an active absorber are designed for implementation and testing on a full scale mock-up of a Cobra helicopter wing. (Modified author abstract)

Descriptors :   *Rocket launchers, *Vibration isolators, Dynamic response, Helicopters, Damping, Numerical analysis, Servomechanisms, Gun mounts

Subject Categories : Rockets

Distribution Statement : APPROVED FOR PUBLIC RELEASE