Mid I
Mid I
Mid I
Problem 1
A building frame is modeled as an undamped single degree of freedom system (Fig. a). Find
the response of the frame if it is subjected to a blast loading represented by the triangular
pulse as shown in (Fig. b).
Problem 2
(a) Derive the equation of motion for the system shown in terms of the coordinate x .
(b) Find the steady state response of the system.
Assume small oscillations. The lever AOC has mass moment of inertia J O .
Problem 3
Determine the values of k and c for the system shown if the damped period of vibration is to
be 0.3 s and the amplitude of vibration of the system decays to half of its initial value in 6
cycles.
J 0 2.4 kg.m 2 , m 5 kg, r1 0.2 m, r2 0.4 m.
t
1
m n 0
x(t ) F ( ) sin n (t ) d
1
sin n (t )d
n
[cos n (t )]
cos n (t ) sin n (t )
sin n (t )d
n
n2
F0
X
k m c 2 2 2 2
1/ 2
c
tan 1 2
k m
cc 2m n
c
cc
d n 1 2
2
d
d
x1
e n n d
xn 1