This document discusses two types of mechanical motion: translational and rotational.
Translational motion involves moving an object along a linear axis rather than rotating it, and is described using mass, springs, and dampers. Rotational motion involves rotating an object about its own axis and is described using moment of inertia, rotational springs, and rotational dampers.
The key elements used to model both translational and rotational systems - mass/moment of inertia, springs, and dampers - produce forces or torques proportional to displacement, velocity, or acceleration based on their material properties like stiffness or damping coefficient.
3. Introduction:
Basic Types of Mechanical Systems:-
Translational
◦ Linear Motion
Rotational
◦ Rotational Motion
4. As stated earlier translational motion refers to a type
of motion in which a body or an object mores along a
linear axis rather than a rotational axis.
Hence translational motion is also referred to as
linear motion. Translational motion involves moving
left or right, forward or backward, up or down
Translational Motion
5. We will discuss translational motion using the
following three basic elements viz.
1.Mass
2.Spring
3.Damper
6. Translational Mass
Translational
Massii)
• Translational Mass is an
inertia element.
• A mechanical system
without mass does not
exist.
• If a force F is applied to a
mass and it is displaced to
x meters then the relation
b/w force and
displacements is given by
Newton’s law.
M
)(tF
)(tx
xMF
7. Translational
Spring
i)
Circuit Symbols
Translational Spring
A translational spring is a mechanical
element that can be deformed by an
external force such that the deformation is
directly proportional to the force applied
to it.
Translational Spring
8. Translational Spring
If F is the applied force
Then is the deformation if
Or is the deformation.
The equation of motion is given as
Where is stiffness of spring expressed in N/m
2x
1x
02 x1x
)( 21 xx
)( 21 xxkF
k
F
F
9. Translational Damper
Translational
Damperiii)
• When the viscosity or drag
is not negligible in a system,
we often model them with
the damping force.
• All the materials exhibit the
property of damping to
some extent.
• If damping in the system is
not enough then extra
elements (e.g. Dashpot) are
added to increase damping.
11. Rotational motion is motion about its own axis. In
such systems, force gets replaced by Torque (T),
displacement by angular displacement (θ), velocity
by angular velocity (w) and acceleration by angular
acceleration (α)
Spring and friction behave in the same manner as in
translational motion except for that displacement
changes to angular displacement and velocity changes
to angular velocity
Rotational Motion
12. We shall discuss rotational motion using the
following three elements viz.
1.Inertia
2.Damper
3.Spring
13. Basic Elements of Rotational Mechanical Systems
1. Rotational Spring
)( 21 kT
2
1
14. Basic Elements of Rotational Mechanical Systems
2.Rotational Damper
2
1
)( 21 CT
T
C
15. Basic Elements of Rotational Mechanical Systems
3. Moment of Inertia
JT
TJ