Page 12 - Vibrations 5

−0.2 −0.4 1
( ) ( ) =
−0.2 −2/5 2

or

1 2 1
( ) ( ) =
1 2 2

+ 2 = 0 leaving = − /2
1
2
1
2
The mode shape for the natural frequency is
1
1
= ( −1/2 )
1

Using the second eigenvalue,

0.8 − 2/5 −0.4 1
( ) ( ) =
−0.2 0.6 − 2/5 2

or

2/5 −0.4 1
( ) ( ) =
−0.2 1/5 2

or

2 −2 1
( ) ( ) =
−1 1 2

Leaving − + = 0 =
2
1
1
2
The mode shape for the natural frequency is
2

1
= ( )
2
1

You will remember,

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