Design and Stress Analysis of Extraterrestrial ... - The Black Vault

!I
As is apparent from Fig. 2.39, the increase in shell radius at
working pressure is 0.9.1-,3 m. The stress in the outer shell i!
al = 30'i07 N/m 'and in the inner shell is a' = -6.107 N/mr 2 ; the
latter stress is compressive which is explained by •theŽgreat thermal
elongation of the inner shell., If the working pressure were higher
the stress in the inner shell would e tensile stress.
Fig. 2.,39. The stressed state - - -
of shells as a function of
p
radial strain. ---- -...-.-
Ia ., - -
60 --
01-i
~-20
The curves presented in Fig. 2.39 show that when p = 0 there
is a certain strained state caused by the thermal expansion of the
inner shell.
It is important to note that on the pressure variation curve
two sections of shprp increase are observed. The first section with
low AR and the second with AR z 0.9"l1-
3
m. This is explained as
follows. If the pressure is low, the external shell operates
elastically and.with a rise in
pressure, strains slowly increase.
If the pressure is •reater than a certain magnitude, in the outer
shell plastic flow will occur; now it
will be loaded not only by the
*1 forces of pressure but also by forces from the direction of the
inner and more severely heated shell. A rapid increase in AR occurs
with an insignificant rise in pressure.
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