Unit-4 One Marks
Unit-4 One Marks
Unit-4 One Marks
PART-A (1 marks)
etc.
2. The materials used for vibration isolation are rubber, felt cork, etc. These are placed
between the foundation and vibrating body.
When the particles of a shaft or disc move in a circle about the axis of the shaft, then the
vibrations are known as torsional vibrations.
1. In transverse vibrations, the particles of the shaft move approximately perpendicular to the
axis of the shaft. But in torsional vibrations, the particles of the shaft move in a circle about
the axis of the shaft.
2. Due to transverse vibrations, tensile and compressive stresses are induced. Due to
torsional vibrations, torsional shear stresses are induced in the shaft.
Node is the point or the section of the shaft at which amplitude of the torsional vibration is
zero. At nodes, the shaft remains unaffected by the vibration.]
6. Define torsional equivalent shaft.
A shaft having variable diameter for different lengths can be theoretically replaced by an
equivalent shaft of uniform diameter such that they have the same total angle of twist when
equal opposing torques are applied at their ends. Such a theoretically replaced shaft is known
as torsionally equivalent shaft.
7. What are the conditions to be satisfied for an equivalent system to that of geared
system in torsional vibrations?
1. The kinetic energy of the equivalent system must be equal to the kinetic energy of the
original
system.
2. The strain energy of the equivalent system must be equal to the strain energy of the
original system.