<DOC>
<DOCNO>
739
</DOCNO>
<TITLE>
the buckling of thin cylindrical shells under axial
compression .
</TITLE>
<AUTHOR>
von karman,t. and tsien,h.s.
</AUTHOR>
<BIBLIO>
j. ae. scs. 8, 1941, 303.
</BIBLIO>
<TEXT>
in two previous papers the authors have discussed
in detail the inadequacy of the classical theory of
thin shells in explaining the buckling phenomenon of
cylindrical and spherical shells .  it was shown that
not only the calculated buckling load is 3 to 5 times
higher than that found by experiments, but the observed
wave pattern of the buckled shell is also different
from that predicted .  furthermore, it was pointed
out that the different explanations for this discrepancy
advanced by l. h. donnell and w. flugge are untenable
when certain conclusions drawn from these explanations
are compared with the experimental facts .
by a theoretical investigation on spherical shells the
authors were led to the belief that in general the
buckling phenomenon of curved shells can only be explained
by means of a non-linear large deflection theory .
this point of view was substantiated by model experiments
on slender columns with non-linear elastic support
.  the non-linear characteristics of such structures
cause the load necessary to keep the shell in equilibrium
to drop very rapidly with increase in wave amplitude
once the structure started to buckle .  thus, first
of all, a part of the elastic energy stored in the shell is
released once the buckling has started,. this explains
the observed rapidity of the buckling process .  furthermore,
as it was shown in one of the previous papers
the buckling load itself can be materially reduced by
slight imperfections in the test specimen and vibrations
during the testing process .
  in this paper, the same ideas are applied to the case
of a thin uniform cylindrical shell under axial compression
.  first it is shown by an approximate calculation
that again the load sustained by the shell drops
with increasing deflection .  then the results of this
calculation are used for a more detailed discussion of
the buckling process as observed in an actual testing
machine .
</TEXT>
</DOC>
