<DOC>
<DOCNO>
908
</DOCNO>
<TITLE>
random vibration .
</TITLE>
<AUTHOR>
crandal,s.
</AUTHOR>
<BIBLIO>
app. mech. rev. 12, 1959, 739.
</BIBLIO>
<TEXT>
  random vibration is vibration which results
from an excitation which is not well represented by any simple
function (sinusoid, step, etc.) or any simple combination of
such functions but which is satisfactorily modeled by a stochastic
process .  it is perhaps not too much of an exaggeration
to say that /all vibration is random vibration ./  every vibration
record contains /hash/ at some level .  nevertheless,
until recently, engineering vibration theory has been able to
get along without including the consideration of random excitations
.
  now in several fields simultaneously there has occurred a
burst of activity in the application of random processes .  the
response of aircraft to buffeting from atmospheric turbulence
and the response of ships to confused seas have been put on
reasonably firm footing .  possibly the most dramatic problems
have been posed by the development of large jet and rocket
engines which produce spectacular amounts of random vibrational
energy .  the high level of random vibration in a jet
plane or a missile provides a severe environment with respect
to fatigue failure of structural members and with respect to
malfunctions of sensitive equipment .
</TEXT>
</DOC>
