<DOC>
<DOCNO>
859
</DOCNO>
<TITLE>
flutter of aerodynamically heated aluminium-alloy and
stainless steel panels with length-width ratio of 10
at mach 3. 0.
</TITLE>
<AUTHOR>
guy,l.d. and bohon,h.l.
</AUTHOR>
<BIBLIO>
nasa tn.d1353, 1962.
</BIBLIO>
<TEXT>
  an investigation of the effects of aerodynamic heating on the flutter
of multibay external-skin panels has been carried out at a mach number
of 3.0 in the langley 9- by 6-foot thermal structures tunnel .  both
aluminum-alloy and 17-7 ph stainless-steel panels with a length-width
ratio of 10 for each bay were tested at dynamic pressures between
addition, a few tests were made on the lower vertical stabilizer of the
x-15 airplane which has external-skin panels unsupported for a length
  all panels showed flutter boundaries characterized by an increase
in panel thickness required to prevent flutter with increasing thermally
induced stress prior to buckling .  after buckling the panels showed
flutter boundaries characterized by a decrease in thickness required to
prevent flutter with further increases in thermal stress .  the largest
thickness required to prevent flutter in the presence of aerodynamic
heating occurred at the transition between the flat-panel boundary and
the buckled-panel boundary .  this peak value (for aluminum-alloy panel)
was as much as 60 percent greater than the extrapolated value for an
unheated, unloaded panel .
  values of the modified-thickness-ratio flutter parameter for the
unstressed panels (obtained by extrapolation) were in fair agreement for
the aluminum, steel, and x-15 stabilizer panels .  peak values at
transition, however, showed large differences due to apparently minor
changes in panel-support construction and or changes in panel-skin
material .
</TEXT>
</DOC>
