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

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is determined by the principal stresses ar <strong>and</strong> 11, which reach<br />

their highest value on its surface.<br />

Near the openings there is a certain concentration <strong>of</strong> stresses,<br />

which is substantial for plates oi brittle materials. For the<br />

materials <strong>of</strong> plates used in reactors this concentration <strong>of</strong> stresseý<br />

can be disregarded.<br />

can write<br />

Based on the similarity <strong>of</strong> bending curves for the plates, we<br />

W<br />

Wa (2.77)<br />

where y Js the coefficient <strong>of</strong> proportionality allowing for the<br />

reduction in plate rigidity due to its perforation.<br />

Let us find the value <strong>of</strong> y from a comparison <strong>of</strong> the deflections<br />

<strong>of</strong> perforated <strong>and</strong> solid plates. For the plate shown in Fig. 2.57<br />

the deflections<br />

I&, p 1 2 -- r 2 )2 ;Wp(h2 -rj4)2<br />

64D<br />

64D<br />

hence (w)/(wn), = y =<br />

n<br />

(Dn)/(D). n<br />

Thus, the cylindrical rigidity <strong>of</strong> a perforated plate is equal<br />

to the rigidity <strong>of</strong> a nonperforated plate multiplied by the coefficient<br />

<strong>of</strong> perforations y. This makeF it possible, in the first approach,<br />

to find the stresses <strong>of</strong> a perforated plate from formulas for a solid<br />

plate, correcting for the reduction in rigidity due to perforation.<br />

Cylindrical rigidities are<br />

Dý--<br />

Eh3<br />

Dn=.<br />

12(1!P)12(8<br />

9h1<br />

185

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