01.07.2014 Views

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

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

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

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

1 JVQP<br />

(3.30')<br />

Fig. 3.24. Forms <strong>of</strong> flexural UT<br />

blade vibrationis.<br />

I<br />

KEY: (1) lst form; (2) 2nd form; 0I- -jOpM1 (i).<br />

(3) 3rd form.<br />

014 J-opR.,,, (3)<br />

0.<br />

0,2 09 ý 0,81<br />

Accordingly, the vibration fxrequency (in Hz) for this case is<br />

n. j1; Bi<br />

h -F<br />

2 12 V (3.25')<br />

-Integral method <strong>of</strong> determining the natural<br />

frequencies <strong>of</strong> blade vibrations<br />

This method <strong>of</strong> determining the natural frequencies <strong>of</strong> blade<br />

vibrations, as indicated, is appropriate for only the simplest case<br />

when a blade has a constant temperature along its length <strong>and</strong> the<br />

cross section is constant. However, for the majority <strong>of</strong> the problems<br />

this solution is not appropriate. <strong>The</strong>refore, let us examine the<br />

_general case <strong>of</strong> a vibrating blade which has F ý const; EI• $ const.<br />

<strong>The</strong> initial differential equation <strong>of</strong> natural oscillations was<br />

obtained above (3.o23):<br />

268

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!