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

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:I<br />

I I I<br />

<strong>The</strong> first equilibrium equation for an element cut out' <strong>of</strong> a<br />

cylindrical wall is obtained from expression (2.30) by substituting<br />

R 1 =<br />

<strong>and</strong> R 2 =R:<br />

* (2.33)<br />

<strong>The</strong> stress a =<br />

we find by dividing the forces acting on the<br />

bottom by the cross section <strong>of</strong> the shell. As we know, if uniformly<br />

distributed pressure acts on any surface? then, regardl~ss <strong>of</strong> the<br />

shape <strong>of</strong> the surface (see 1, 2, 3 on Fig. 2.25b), the projection <strong>of</strong><br />

the equally acting forces <strong>of</strong> pressure onto a givep axis is' equal t6<br />

the product <strong>of</strong> the pressure p times the area <strong>of</strong> the surface projectioh<br />

onto a plane perpendicular to the axis.<br />

Fig. 2.24. Formation <strong>of</strong> a =6<br />

welded seam in a spherical<br />

shell.<br />

ifConsequently, regardless <strong>of</strong> the shape <strong>of</strong> the bottom, the for'e<br />

pulling the shell in the direction <strong>of</strong> the x-axis,<br />

4I<br />

Cosqety egrls fte hp ftebotm h o'<br />

<strong>and</strong> the stress<br />

pulin<br />

2i-Rh 2h 54.3)<br />

nte thhhl ieto fth -xs1<br />

133

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