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

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Dependence (5.104) is plotted in Fig. 5.60a. Pre'ernted also<br />

are the result <strong>of</strong> the analysis <strong>of</strong> a plate which can be displaced it,<br />

a radial direction (without ';urn) <strong>and</strong> the result <strong>of</strong> analysis accorJill<br />

to formulas for a rigid plate.<br />

Thus, maximum bend <strong>of</strong> the membrane <strong>and</strong> pressure p are connected<br />

by a cubic dependence. With small bends the term containing the<br />

third power <strong>of</strong> ratio w 0 /h can be disregarded; dependence (5.1011)<br />

converts to the earlier presented dependences for a £'igid plate.<br />

<strong>The</strong> curves in Fig. 5.60a show that with a growth in bend the<br />

rigidity <strong>of</strong> a flexible plate increases. With bends <strong>of</strong> w/h > 1 the<br />

plate should be assumed flexible.<br />

However, this method <strong>of</strong> analyzing deflections Qf a flexible pt.f,-<br />

is not universal. It has good agreeme,- with precis( calc:lat.ion<br />

<strong>and</strong> practice when w/h < 4.<br />

<strong>The</strong> method requires refinement if the deflections exceed this<br />

value. Actually, when examining the elastic surface <strong>of</strong> a olate,<br />

as deflections increase we can note a displacement <strong>of</strong> the [2.ih-r<br />

point toward the contour <strong>and</strong> at the limit its agreement .:iill ,:.t<br />

attachment, which contradict, the oasic assumption conct:.,.1ng th,<br />

similarity <strong>of</strong> large bends to benas <strong>of</strong> a rigid plat,-.<br />

f oc ( r)3<br />

05-7).)<br />

We can pr-scribe the 3hape, <strong>of</strong> the elast ic surface [n tbh f,.r.<br />

This expression differs from expression (5.103) by the fact t'..,t<br />

here, instead <strong>of</strong> the exponent 3, there is introduced an undeterm.Lne.,<br />

index z which can be determined each time as a function ol uhe<br />

specific relationship between load <strong>and</strong> plate thickness.<br />

SJthe transformations, we .,býain<br />

I nEh4-- pb<br />

th ) "a k3<br />

A IfWO -LA3ly-0)3 h-3<br />

On'ittinv<br />

ka" 5. 0""<br />

623<br />

'C

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