Report of the Second Piloted Aircraft Flight Control System - Acgsc.org

EFFECT OF ADDRIG A SPEUNC IllbD AT THE SUBPACE (see Fig. 7.) -
The mtire sptm amlysis to this point has separated the hydraulic 8pt.L
frar eixteraal syataas at the portion of th load schmatic where the
laad F appears. me ruvierlying mason for this procedure was to prorido
a maans of hwxllhg the flutter analysis of the hydraulic system. However,
in the operation of a Wraulic syatem under fUght conditiono, the
force F wlll be tho major load, and a portion of this force may bo a
definite function of ZS . Whem such a force dots, the force F
ceases to be purely an external disturbance and became8 a p h q element
of the inner loop. The sinplest example of this situation exists when
F =As X , or a pun, spring load mch as a static hlnge mment
gradimt is applled to the 8pteno In this went:
An approximate value of the naminal lawest &pal
with Cp ro o
natural frequency is,
As is much less tlnn 4 , so that the lowest undamped
Ilo-Uy
natural f reqamcy is essentially unchanged,
!CEE GEaaaAL mAD CASE
The purpose of this wction is to present the equations for the
eullc opt- with all of the terns taken into account, to indicate
the use of the lgdmullc syaten data in flutter calculations and to Inroetigate
the effects of various stmctural caerponents upon the Mest
&pal natural. frqumcy of the open loop transfer function.