Accession Number : AD0021969


Title :   VIBRATIONS OF A HELICOPTER ROTOR SYSTEM AND FUSELAGE INDUCED BY THE MAIN ROTOR BLADES IN FLIGHT


Descriptive Note : Rept. no. 2


Corporate Author : POLYTECHNIC INST OF BROOKLYN NY DEPT OF AEROSPACE ENGINEERING AND APPLIED MECHANICS


Personal Author(s) : MORDUCHOW, MORRIS ; YUAN, SHAO W ; REISSNER, H


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/021969.pdf


Report Date : Jun 1953


Pagination or Media Count : 32


Abstract : Based on a simplified model of the hub-fuselage structure, a theoretical analysis is made of the response of the hub and fuselage of a helicopter in flight to harmonic forces transmitted by the rotor blades to the hub both in, and normal to, the plan of rotation. The assumed structure is in the form of a plane framework with masses concentrated at the joints. Simple expressions are derived for the vibration amplitudes of the mass points as functions of the masses and natural frequencies of the hub and the fuselage. The pertinent non-dimensional parameters are determined, and simple explicit conditions of resonance are derived. Numerical examples are given to illustrate the results.


Descriptors :   *VIBRATION , *HELICOPTER ROTORS , PARAMETERS , THEORY , ROTOR BLADES(ROTARY WINGS) , RESONANT FREQUENCY , RESPONSE , RESONANCE , FUSELAGES , INFLIGHT , HUBS , AIRCRAFT MODELS , AMPLITUDE , ROTATION , SIMPLIFICATION


Subject Categories : Helicopters


Distribution Statement : APPROVED FOR PUBLIC RELEASE