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

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- all eigenfunctions form an orthogonal set <strong>of</strong> functions<br />

npw : when<br />

1 0 IPH ij--<br />

S ot•tutdz=={<br />

o0 1 11pH i=j<br />

(3.39')<br />

<strong>The</strong> last property is used in determining the natural frequencies<br />

<strong>of</strong> vibrations <strong>and</strong> the form function for orders above the first<br />

(i.e., ( e. wc2 ck <strong>and</strong> uk where k = 2, 3, 4 ... )<br />

Integral equation (3.37) is usually solved by the method <strong>of</strong><br />

successive approximation (simple iteration). <strong>The</strong> advantage <strong>of</strong> this<br />

method is the fact that with it it is possible to calculate a system<br />

where all parameters are given numerically (tabular). As a result<br />

<strong>of</strong> calculation, along with the frequencies, wave forms are obtained<br />

which gives a concrete physical meaning to the solution <strong>of</strong> the<br />

problem.<br />

If a certain function is preset numerically, it is first<br />

necessary to normalize this function.' This means that each value<br />

<strong>of</strong> the function is divided by its norm (usually the norm tj the<br />

peak value <strong>of</strong> the modulus <strong>of</strong> the function in the assigned range <strong>of</strong><br />

variation), i.e.,<br />

'To compare two different functions <strong>of</strong> one class the concept <strong>of</strong><br />

the function norm exists. <strong>The</strong> function norm is the numerical value<br />

<strong>of</strong> the important parameter or a set <strong>of</strong> parameters inherent in all<br />

comparable functions, sometimes simply the "scale" <strong>of</strong> the function.<br />

<strong>The</strong> norm <strong>of</strong> the function is designated 1hull or ul.<br />

A function whose norm is equal to one is called normalized. In<br />

vibration problems for the function norm we usually use the highest<br />

value <strong>of</strong> the modulus <strong>of</strong> a function in a given range cc variation, which<br />

can be dasignated ulmax.<br />

273

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