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Reg
APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
SIXTH SEMESTER B.TECH DEGREE EXAMINATION, APRIL 2018
Course Code: ME304
Course Name: DYNAMICS OF MACHINERY MP, AU, PE)
Max. Marks: 100 Duration: 3 Hours
PART A
Answer any three full questions, each carries 10 marks. Marks
1 The applied load on the piston of an offset slider-crank linkage shown in Fig.1 is
100 and the coefficient of friction between the slider and the guide is 0.27, using
graphical method determine the magnitude and sense of torque applied on OA for
the static equilibrium of the linkage.
O
60o

12 mm
Fig. 1
A
OA 6 cm AB 18 cm
B 100 N

2 Fig. 2 shows a four bar linkage on which various forces acting and their directions
are shown. Determine the magnitude and direction of the torque applied on the link
O1A to keep the equilibrium of the linkage. Also determine the magnitude and
direction of the forces transmitted to the frame of the linkage. Use Matrix method.
30o
O4
O1
A
60C o
D
B
F1= 150 N
O1A 15 cm O4B 25 cm
O1O4 50 cm BD 12.5 cm
BC 0.5 AB

Fig. 2 F2=200 N

3 Two 20o straight bevel gears have a module pitch of 4mm, and 24 and 48 teeth
respectively. The tooth face width is 50 mm. The pinion rotates at 1000 rpm and
transmits 5 kW. The shafts are at 90o. Determine the components of the gear force
and show these on a sketch of the gears.

4 In Fig. 3 a slider crank linkage is shown, in which various accelerations are shown
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and. The crank OA is running in the CCW direction. The mass of the connecting
rod AB is 4 kg and moment of inertia about its mass centre G is 0.052 kg-m2 and
mass of the slider is 2.5 kg. Assume that the crank OA is weightless. Determine the
magnitude and direction of the torque to be applied on the crank to balance the
inertia effects of the linkage
G
T2
40o 200 rad/s2
aB 120 m/s2
A
O
aG 150 m/s2
OA 15 cm AG =15 cm
GB 30 cm
Fig. 3
B
PART B
Answer any three full questions, each carries 10 marks.
5 A constant torque 2.5 kW motor drives a riveting machine. The mass of the moving
parts, including the flywheel is 125 kg at 70 cm radius. One riveting operation
absorbs 10,000J of energy and takes 1.2 seconds. Speed of the flywheel is 240 rpm
before riveting. Determine No. rivets closed per hour and the reduction in
speed after the riveting operation.

6 A shaft carries four rotating masses A of 5 kg, B of C of 4.5 kg, and D of
3.5 kg in this order from left to right. The effective radius of rotation of these
masses from the left are respectively 30 cm, 40 cm, 35 cm and 25 cm. The plane of
rotation of A and B are 35 cm apart and that between Band C are 45 cm apart. The
angle between the A and C is 120o.
Determine the angle between A and B and that between A and D.
Distance between the planes of revolution of C and
the mass mB, so that the system is incomplete balance

7 The turbine rotor of a ship weighs 550 kN and has a radius of gyration of 0.45m
rotating at 2500 rpm in a CW direction when viewed from the aft. Ship pitches
through a total angle of 12o. Assuming that the motion is being simple harmonic
with a period of 15 second, determine the maximum gyroscopic couple on the
holding down bolts of the turbine and using the vector diagram, find the direction of
yaw when the bow rises.

8 Each road wheel of a motor cycle is of 60 cm diameter and has a moment of inertia
of 1.2 kg-m2. The motor cycle and the rider together weighs 250 kg and the
combined centre of gravity is 65 cm above the ground level when the motor cycle is

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upright. The moment of inertia of the rotating parts of the engine is 0.18 kg-m2. The
engine rotates 4.5 times the speed of the road wheel in the same sense. Find the
angle of heel necessary when the motor cycle is taking a turn of 40 m radius at a
speed of 70kmph
PART C
Answer any four full questions, each carries 10 marks.
9 By neglecting the mass of the slender uniform rod is shown in Fig.
determine the natural frequency of free vibration of the mass for small
oscillations

L a
k
Fig. 4 An oscillating pendulum
m

Find the frequency of the oscillations of the system shown in Fig. The
roller rolls on the surface without slipping.
k M r
Fig. A Cylinder rolling on a floor
5
10 A mass of 4.5 kg, hangs from a spring and makes damped vibration. The time of 50
complete oscillations is found to be 18 seconds and the ratio of first down ward
displacement to the sixth is found to be 2.5.
Find the natural frequency of the system,
the stiffness of the spring in
the damping coefficient in
the critical damping coefficient.

11 An electric motor weighing 100 kg is supported on isolators having a damping
factor of 0.2. It runs at a speed of 1500 rpm and has a rotating unbalance of 10 kgcm.
What should be the stiffness of the isolators if the forces transmitted to the
foundation is to be less than 10 of the unbalanced force

12 A rotor has a mass of 12 kg and mounted midway on a 24 mm diameter horizontal
shaft supported at ends by bearings. The bearings are 1 m apart. The shaft rotates at

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2400 rpm. If the centre of mass of the rotor is 0.11 mm away from the geometric
centre of the rotor due to certain manufacturing defects. Find the amplitude of
steady state vibration. Take E 200GPa
13 A centrifugal pump rotating at 400 rpm is driven by an electric motor at 1200 rpm
through a single stage reduction gearing. The moment of inertia of the pump
impeller and the motor are 150 kg-m2 and 450 kg-m2 respectively. The lengths of
the pump shaft and the motor shaft are 500 mm and 200 mm and their diameters are
100 mm and 50 mm respectively. Neglecting the inertia of the gears, find the
frequency of torsional oscillations of the system, and draw the mode shape.
TakeG 82 GPa

14 What do you understand by vibration pickups? With neat diagram explain the
working of a seismometer.