Mechanics was among the first of the exact sciences to be developed. Its internal beauty as a mathematical discipline and its early remarkable success in accounting in quantitative detail for the motions of the Moon, Earth, and other planetary bodies had enormous influence on philosophical thought and provided impetus for the systematic development of science. Mechanics may be divided into three branches: statics, which deals with forces acting on and in a body at rest; kinematics, which describes the possible motions of a body or system of bodies; and kinetics, which attempts to explain or predict the motion that will occur in a given situation. Alternatively, mechanics may be divided according to the kind of system studied. The simplest mechanical system is the particle, defined as a body so small that its shape and internal structure are of no consequence in the given problem. More complicated is the motion of a system of two or more particles that exert forces on one another and possibly undergo forces exerted by bodies outside of the system. The principles of mechanics have been applied to three general realms of phenomena. The motions of such celestial bodies as stars, planets, and satellites can be predicted with great accuracy thousands of years before they occur. (The theory of relativity predicts some deviations from the motion according to classical, or Newtonian, mechanics; however, these are so small as to be observable only with very accurate techniques, except in problems involving all or a large portion of the detectable universe.) As the second realm, ordinary objects on Earth down to microscopic size (moving at speeds much lower than that of light) are properly described by classical mechanics without significant corrections. The engineer who designs bridges or aircraft may use the Newtonian laws of classical mechanics with confidence, even though the forces may be very complicated, and the calculations lack the beautiful simplicity of celestial mechanics. The third realm of phenomena comprises the behaviour of matter and ele

1. CENTER FOR INVENTION, INNOVATION, INCUBATION & TRAINING
(CIIIT)
Government College of Engineering Chandrapur
Name of Students :
1. Vivek Atalkar
2. Aniket Awate
3. Abhishek Bawane
4. Sumit Dhodare
5. Pranay Ghatode
Department of Mechanical Engineering
Guided by : Atul Bihure, Arpit Agrawal

2. BASIC OF MECHANICS

3. CONTENTS
 Introduction to Mechanics
 Simple Lifting Machine
 Kinematics of Machine
 Loads & Beam
 Stress Strain Curve

4. Introduction to
Mechanics
It is a branch of engineering which deals with the
behavior of a body when the body is at rest or in
motion.
What is Mechanics?

5. Mechanics
Statics
(Body At Rest)
Dynamics
(Body In Motion)
Kinematics
(The Forces Which Cause
motion Are Not Considered)
Kinetics
(The Forces Which Caused
Motion are Considered)
CLASSIFICATION OF
MECHANICS

6. Statics :
It deals with the study of forces acting on machines
parts when the body is at rest or in equilibrium
position.
Dynamics :
It deals with the study of forces acting on machine
parts when the body is in motion.

7. Kinetics :
It deals with the study of forces acting on
machines parts including inertia forces (inertia
forces are the combine effect of the mass & the
motion of the parts).
Ex: Friction, Torque, etc.
Kinematics :
It deals with the study of relative motion of
machine parts only. It is not concerned with the
forces acting on machine parts.

8. Basic terms used in
mechanics
Some Basic Terms Used In Mechanics
Force: Force is an external agent capable of changing a
body's state of rest or motion. Its SI unit is Newton.
Displacement: It is defined as the shortest distance
covered by a body/particle in the specified direction.
Velocity: The rate of change of displacement with respect
to time is defined as velocity.
Acceleration: It is the rate of change of velocity with
respect to time.

9. Basic terms used in
mechanics
Momentum: The product of mass and velocity is called
momentum. Thus
Momentum = Mass × Velocity
Torque: It is a measure of the force that can cause an object
to rotate about an axis.

10. Simple lifting machine
Simple lifting machine is the device used to lift
a heavy load by applying comparatively smaller
force or effort.
Mechanical Advantage:
It is the ratio of load lifted by a machine to
effort applied.
M.A. =
Mechanical Advantage (M.A.) is always greater
than 1.
Load
Effort

11. Types of Simple Lifting Machine
1. Pulley
2. Screw
3. Lever
Pulley: A pulley is a simple machine
that consists of a rope and grooved
wheel. The rope fits into the groove in
the wheel, and pulling on the rope
turns the wheel. Pulleys are generally
used to lift objects, especially heavy
objects.
Application: Shipping & Marine
used, Industry, Elevators, etc.
Simple lifting machine

12. Simple lifting machine
Screw: A screw jack is used to lift a heavy load by
applying smaller effort. It consists of a screw, fitted in a
nut, which forms the body of the jack and a screw head
to which a handle is attached. The load is kept on the
screw head and effort is applied by the handle.
Application: Lifting cars and trucks, lifting machinery
for assembly purpose, etc.

13. Simple lifting machine
Lever: A lever is a simple machine made of a rigid beam
and a fulcrum. The effort (input force) and load (output
force) are applied to either end of the beam. The fulcrum
is the point on which the beam pivots.
Application: See-saw, scissors, plier, etc.

14. Kinematics
of
Machine
Kinematics of Machine
As we seen earlier, Kinematics of Machine deals
with the study of relative motion of machine parts
only. It is not concerned with the forces acting on
machine parts.
It is the study from geometric point of view to know
the displacement, velocity & acceleration of a part
of a machines.

15. Mechanism :
A mechanism is made up of no. of resistant bodies
out of which some may have motion relative to the
others.
The primary function of mechanism is to modify or
transmit motion.
Machine :
Machine is made up of no. of mechanism.
Machines are used to transform some available
form of energy or motion into another form which is
necessary for the performance of specified
operation.
They must transfer both forces and motions.

16. KinematicLink
A resistant body which is a part of a machine and
has motion relative to other connected parts is
termed as a link or an element. It is also called as
Kinematic Link.
Types of Kinematic Link :
i. Rigid link
ii. Flexible link

17. 1
Kinematic
chain
Kinematic Chain :
It is the combination of no. of kinematics link such
that first link is joint with last link in which the relative
motion of link is possible.
2
3
1
4

18. Four Bar Chain / Mechanism
Four bar chain or mechanism is made up of four
links in which one link is fixed and other three links
having relative motion to each other.
It converts rotary motion into oscillatory motion.
Four bar mechanism

19. Four bar mechanism
Crank
Rocker / Lever
Connecting Rod

20. Single Slider Crank Chain / Mechanism
A slider crank mechanism converts the
reciprocating motion of the slide to the rotary
motion of the crank and vice versa.
However when it is used as an automobile
engine by adding the valve mechanism it
becomes a machine which converts available
energy into desired energy.
Examples: Steam Engine, Reciprocating pump
Single slider crank
mechanism

21. Single slider crank
mechanism

22. Beams
&
Loads
Beam :
Structural member which carries the transverse
load or force (force which acting perpendicular to
the longitudinal axis of structure.
Type of Beams:
Simply supported beam
Cantilever beam
Overhanging beam
Fixed beams
Continuous beam

23. beams
Simply Supported Beam
Application :
Bridges, beams in buildings, and beds of machine
tools.

24. beams
Cantilever Beam
Application :
Street signs, airplane wings, shelves, fan blades, and
some bridges are all examples of cantilevers

25. beams
Overhanging Beam
Application :
An overhanging beam is used where it is not
practical to provide a support to the beam at one
end.

26. beams
Fixed Beam
Application :
Fixed beams provide sturdiness to the structure. They
are used to withstand both horizontal and vertical
forces. Installing them in a sloppy roof of a house is
how you can put them to the best use. All of the
strength of such a structural element comes from two
load-bearing fixed ends.

27. beams
Continuous Beam
Application :
Continuous beams are used in bridges, multi-story
buildings, complex roof structures, and other
construction projects.

28. lOADS
Loads
The external force acting on the section or
member. For study of shear force and bending
moment, we classify the load into following
manner:-
1. Point load or concentrated load
2. Uniform distributed load
3. Uniformly varying load

29. lOADS
Point load or concentrated load
The load which act on a single point of any
section or member, although in practice it must
really be distributed on very small area.

30. lOADS
Uniform distributed load
The load which is spread over a beam or
section uniformly along the length. It is
expressed as w N/m. It is represented by u.d.l.

31. lOADS
Uniformly varying load
The load which is spread on the section of
member such that rate of loading varies from the
point to point as shown in the below figure in
which load at one section is zero and increase
uniformly to the other end. It is also known as
triangular load.

32. Stress strain curve

33. REGIONS IN
STRESS STRAIN
CURVE
Typical regions that can be observed in a
stress-strain curve are:
 Elastic region
 Yielding
 Plastic region
 Strain Hardening
 Necking and Failure

34.  Elastic Region :
If the specimen returns to its original length when the
load acting on it is removed, it is said to response
elastically.
 Yielding and Plastic Deformation :
A slight increase in stress above the elastic limit will
result in permanent deformation. This behavior is
called yielding. The stress that causes yielding is
called yield stress sy
The deformation that occurs is called plastic
deformation.

35.  Strain Hardening :
A further load can be applied to the specimen,
resulting in a cure that rises continuously but
becomes flatter until it reaches a maximum stress
referred to as ultimate stress, Su
The rise in the curve is called Strain Hardening.

36.  Necking and failure:
After the ultimate stress, the cross-sectional area
begins to decrease in a localized region of the
specimen, instead of over its entire length. The load
(and stress) keeps dropping until the specimen
reaches the fracture point.

38. Thank You