q q
SOLUTIONS
,TableofContents q q
1. Single-Degree-of-Freedom Systems q
2. Random Vibrationsq
3. Dynamic Response of SDOF Systems Using Numerical Methods
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4. Systems with Several Degrees of Freedom
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5. Equations of Motion of Continuous Systems
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6. Vibration of Strings and Bars
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7. Beam Vibrations
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8. Continuous Beams and Frames q q q
9. Vibrations of Plates q q
10. Vibration of Shells q q
11. Finite Elements and Time Integration Numerical Techniques
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12. Shock Spectra
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, Chapter 1
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1.1 Write the equations of motion for the one-degree-of-freedom systems shown in Figures1.72 (a) … (i). Assume
q q q q q q q q q q q q q q q
that the loading is in the form of a force P(t), a given displacement a(t), or a given rotation t as indicated in the fig
q q q q q q q q q q q q q q q q q q q q q q q q q q
ure.
Figure 1.72 One-degree-of-freedom systems
q q q
, Solutions
(a) (b)
spring force = 3EI / L3 u
q q q q q q
3
spring force = 48EI / L u
q q q q q q 3EI
mu 3 u P(t)
q
q q
48EI L
mu 3 u P(t)
q q q q
L q
(c) (d)
spring force = 3EI / L3 u 3EI / L2 (t)
q q q q q
q q q q q
q
spring force = 3EI / L3
q q q q q u a
q q q mu
q
3EI
q
q
u
q q
3EI
(t)
q
L3 L2
3EI
mu 3 u a 0
q q q q q q
L q
3EI 3EI
mu u
q q
q q a(t) q q
3
L L3
(e) (f)
spring force = EA / Lu
q q q q q
EA spring force = 2 3EI / L3 u 6EI / L3 u
q q q q q q q q q q q
mu u P(t)
q q
q q q q
6EI
L mu
q u P(t)
q q q
L3