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

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I<br />

<strong>The</strong> quaotity Scx consists <strong>of</strong> three terms. <strong>The</strong> first term is<br />

conditioned by dis'lacement u. <strong>The</strong> left end <strong>of</strong> ,the element dx<br />

PI<br />

d X<br />

(Fig. 5.51a) obtains displacement u, <strong>and</strong>, the right end - u + -x.<br />

dx<br />

Displacement w is considered, for the present, equal to zero. <strong>The</strong><br />

length increment rf the element will be (Ou/Ox)dx <strong>and</strong> •the corresponding<br />

elongation per unit length Wu/ax.<br />

I<br />

I<br />

<strong>The</strong> second term is conditioned by displabbment w (Fig..5.51b).<br />

If before deformation the length was dx, after deformation it will<br />

be dx + (wdx/R 1 ). <strong>The</strong> length increment is wdx/R 1 <strong>and</strong> the correspondingi<br />

elongation will be w/RI.<br />

Finally, the third term is<br />

conditioned by tlhe turn <strong>of</strong> the element<br />

dx in the plane <strong>of</strong> the arc <strong>of</strong> the meridian (Fig. 5.51,c) in the<br />

absence <strong>of</strong> displacemernt u. Segment AB' is larger than segnient AB<br />

by she quantity (,dx/cos e) - dx. Corresponding elongation is<br />

(1 - cos 0)/cos 0 - 02/2. Since angle 0 = Ow/ox, elongati6n is<br />

I /0t'•.2<br />

it<br />

This quantity is a quadratic functioh <strong>of</strong> bend. With snall bends<br />

can be disregarded.'<br />

St •C'#I a+ d--<br />

Fig. 5.52. Finding t1he ' Rzt;0<br />

circular deformation <strong>of</strong> A"<br />

an element.<br />

IA<br />

Summing the obtained expressions, we find<br />

OU W_.. 0 27 .<br />

OX-<br />

,± 2Z -(ax (5-77)<br />

604

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