Dynamics of Machines - Part II - IFS.pdf

1.6.11 Superposition of Transient and Forced Vibrations in Time Domain (Simulation)
(a)
(c)
(e)
y(t) [m]
y(t) [m]
2.5
2
1.5
1
0.5
0
−0.5
−1
−1.5
−2
(a) Excitation Frequency : 0.1 Hz
−2.5
0 5 10 15
time [s]
20 25 30
−2.5
0 5 10 15
time [s]
20 25 30
y(t) [m]
2.5
2
1.5
1
0.5
0
−0.5
−1
−1.5
−2
2.5
2
1.5
1
0.5
0
−0.5
−1
−1.5
−2
(a) Excitation Frequency : 0.8 Hz
(a) Excitation Frequency : 0.9 Hz
−2.5
0 5 10 15
time [s]
20 25 30
(b)
(d)
(f)
y(t) [m]
y(t) [m]
y(t) [m]
2.5
2
1.5
1
0.5
0
−0.5
−1
−1.5
−2
(a) Excitation Frequency : 0.7 Hz
−2.5
0 5 10 15
time [s]
20 25 30
2.5
2
1.5
1
0.5
0
−0.5
−1
−1.5
−2
(a) Excitation Frequency : 0.8702 Hz
−2.5
0 5 10 15
time [s]
20 25 30
2.5
2
1.5
1
0.5
0
−0.5
−1
−1.5
−2
(a) Excitation Frequency : 1.0 Hz
−2.5
0 5 10 15
time [s]
20 25 30
Figure 19: Time response of the system with 1 D.O.F. excited by forces with different frequencies
(a) ω = 0.1 Hz (before resonance); (b) ω = 0.7 Hz; (before resonance); (c) ω = 0.8 Hz (before
resonance but close – beating); (d) ω = 0.8702 Hz (at resonance); (e) ω = 0.9 Hz (after
resonance but close – beating); (f) ω = 1.0 Hz (after resonance).
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