widely adopted approaches to handle this rather complicated
situation are time-hardening and strain-hardening
rules@71. In general, predictions based on these two
approaches are quite different, and a choice between
them should depend on the comparison of their predictions
with experimental data.
Another key element is initial imperfections which, on
many occasions, are directly resulted from the unavoidable
inaccuracy of manufacturing process. It has been
shown that initial imperfections have a great impact on
reducing buckling pressures of spherical shells in both
static and dynamic responses[8-IO]. As to their influence
in the creep buckling analysis, there has been an indication
that the collapse time of cylindrical shells is

very much affected by the imperfection

magnitude [ 11,121.
In an earlier creep buckling analysis of shallow
tThe research reported on here was supported by the Office of

Naval Research, Contract Number NAVY 00014-75-C-0946.

این مطلب را هم بخوانید :

spherical shells[2], a huge discrepancy was found between
theoretical predictions and experimental results on