7.4 Response of MDF Systems Under the Action of Transient Forces
271
Mode
Mass point
φ
(r )
i
F
i
F
2
φ
(r )
i
m
i
(m iφi(r
)
2
ξ rst
1
1
1.000
−5 × 10 5
−5 × 10 3
2
× 10 4
2
× 10 4
p 2
1 = 1936
ξ 1st
=
9.752×10 5
1924.733×3.3792×10 4
= 0.015 m.
2
0.7594
15
× 10 5
−11.391 × 10 3
2
× 10 4
1.1533
×10 4
3
0.3361
10
× 10 5
3.361
× 10 3
2
× 10 4
0.2259
× 10 4
9.752
× 10 3
3.3792
× 10 4
2
1
1.000
−5 × 10 5
−5 × 10 5
2
× 10 4
2
× 10 4
p 2
2 = 14400
ξ 2st
=
−28.6425×10 5
14400×5.2684×10 4
= 0.003775 m
2
−0.8047
15
× 10 5
−12.071 × 10 5
2
× 10 4
1.2951
× 10 4
3
−1.1572
10
× 10 5
−11.572 × 10 5
2
× 10 4
2.6782
× 10 4
−28.6425 × 10 5
5.2684
× 10 4
3
1
1.000
−5 × 10 5
−5 × 10 5
2
× 10 4
2
× 10 4
p 2
3 = 27889
ξ 3st
=
−16.285×10 5
27889×26.4×10 4
= −0.00022 m
2
−2.427
15
× 10 5
−36.405 × 10 5
2
× 10 4
11.78
× 10 4
3
2.512
10
× 10 5
25.12
× 10 5
2
× 10 4
12.62
× 10 4
−16.285 × 10 5
2
× 10 4
26.4
× 10 4