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

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Equations (5.74), (5.75), (5.76) should be fulfilled by the<br />

equations <strong>of</strong> shell deformations.<br />

Let us examine shell deformation.<br />

As already indicated, the<br />

geometry <strong>of</strong> a shell is wholly determined by the radius <strong>of</strong> curvature<br />

<strong>of</strong> the arc <strong>of</strong> the meridian RI, by the second principal radius R2,<br />

<strong>and</strong> by angle 0 between the normal to the middle surface <strong>and</strong> the<br />

axis <strong>of</strong> symmetry. <strong>The</strong> shape <strong>of</strong> the middle surface after deformation<br />

is called the elastic surface <strong>of</strong> the shell. It can be characterized<br />

by three projections <strong>of</strong> the full displacement <strong>of</strong> point A onto the<br />

x-, y-, <strong>and</strong> z-axes. Let us designate these projections it, v, <strong>and</strong> w,<br />

respectively (see Fig. 5.49).<br />

AAB<br />

dxd<br />

d<br />

Fig. 5.51.<br />

Finding the radial deformation <strong>of</strong> anl elemlent.<br />

<strong>The</strong> x-axis <strong>and</strong> the di•splacement <strong>of</strong>' u are directed atlong the ta4ngvent<br />

to the arc <strong>of</strong> the meridian, y <strong>and</strong> z along the tangent to •'. aoc c<br />

the circle, <strong>and</strong> z <strong>and</strong> w along the normal. '7ef If shell rm,,t'3r if<br />

axisymmetrAc, displacement od v vanishes.<br />

F.We shall express the deformation arising in the shell In terti.<br />

displacements <strong>of</strong> u, v, <strong>and</strong> w. We find the componento <strong>of</strong> d.,forr..a:' ic.<br />

CX,<br />

C cxy<br />

Cy., <strong>and</strong> yxy in the middle surface <strong>and</strong> designate them %c.' Co),<br />

603

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