<DOC>
<DOCNO>
1019
</DOCNO>
<TITLE>
note on creep buckling of columns .
</TITLE>
<AUTHOR>
</AUTHOR>
<BIBLIO>
</BIBLIO>
<TEXT>
  a method for estimating allowable
load capacities of columns subject
to creep is presented .  the method,
which utilizes approximate stress distributions
derived from isochronousstress-strain
curves to estimate
column load capacities, is shown to
be conservative for the time for which
the estimate is made .
  an application of the method is
made to test data on as-received and
on stabilized 24s-t4 aluminum alloy .
a comparison of the computed column
capacities with experimental capacities
indicates that the method is satisfactory
for estimating the decrease in
capacity with increasing time .
  easily obtained, time-dependent tangentmodulus
loads are discussed .
they are interpreted as being approximations
to allowable load-capacity
estimates .  a limited application is made to
test data, and the results
appear promising .  it is concluded that if
certain limitations are recognized,
the method may prove to be useful because
of its simplicity .
  a presentation of the results of an
experimental investigation of the
effects of column imperfection and columnmaterial
variation is made .  it
is found that column-capacity variations of
the order of 10 per cent can
result from column-imperfection differences
and column-material variation .
  the results of an experimental study of
the variation of column capacity
with temperature of exposure are presented .
they indicate that column
efficiency, as measured by decrease in capacity,
can be acceptable for very
short times at the higher temperatures .  the
efficiency at these higher temperatures
falls rapidly, however, with increasing time .
</TEXT>
</DOC>
