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DYNAMICS OF MACHINE
UNIT: 1Prepared by:
Jasvinder Singh
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CONTENTS INTRODUCTION ABOUT TURNING MOMENT DIAGRAM
TURNING MOMENT DIAGRAM FOR A SINGLE CYLINDER DOUBLE
ACTING STEAM ENGINE TURNING MOMENT DIAGRAM FOR A FOUR STROKE CYCLE INTERNAL
COMBUSTION ENGINE
TURNING MOMENT DIAGRAM FOR A MULTI-CYLINDER ENGINE
DETERMINATION OF MAXIMUM FLUCTUATION OF ENERGY
COEFFICIENT OF FLUCTUATION OF ENERGY
FLYWHEEL
DIFFERENCE BETWEEN GOVERNOR & FLYWHEEL
COEFFICIENT OF FLUCTUATION OF SPEED
ENERGY STORED IN A FLYWHEEL
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CONTENTS
STATIC FORCE ANALYSIS
STATIC EQUILIBRIUM
FREE BODY DIAGRAM
ANALYSIS OF STATIC FORCES IN MECHANISM
DYNAMICS FORCES IN MECHANISMS
DALEMBERTS PRINCIPLE
EQUIVALENTS OFFSET INERTIA FORCE
DYNAMICS OF RECIPROCATING PARTS
(a) PISTON EFFORT
(b) CRANK EFFORT
EQUIVALENT DYNAMICAL SYSTEM INERTIA FORCE IN RECIPROCATING ENGINES BY GRAPHICAL METHOD
ANALYTICAL METHOD FOR INERTIA TORQUE
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INTRODUCTION ABOUT TURNING
MOMENT DIAGRAM
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TURNING MOMENT DIAGRAM FOR A SINGLE
CYLINDER DOUBLE ACTING STEAM ENGINE
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TURNING MOMENT DIAGRAM FOR A SINGLE
CYLINDER DOUBLE ACTING STEAM ENGINE
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TURNING MOMENT DIAGRAM FOR A SINGLE
CYLINDER DOUBLE ACTING STEAM ENGINE
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TURNING MOMENT DIAGRAM FOR A FOUR STROKE
CYCLE INTERNAL COMBUSTION ENGINE
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TURNING MOMENT DIAGRAM FOR A FOUR STROKE
CYCLE INTERNAL COMBUSTION ENGINE
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TURNING MOMENT DIAGRAM FOR A
MULTI-CYLINDER ENGINE
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DETERMINATION OF MAXIMUM
FLUCTUATION OF ENERGY
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DETERMINATION OF MAXIMUM
FLUCTUATION OF ENERGY
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DETERMINATION OF MAXIMUM
FLUCTUATION OF ENERGY
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COEFFICIENT OF FLUCTUATION OF ENERGY
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COEFFICIENT OF FLUCTUATION OF ENERGY
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FLYWHEEL
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DIFFERENCE BETWEEN GOVERNOR &
FLYWHEEL
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COEFFICIENT OF FLUCTUATION OF SPEED
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COEFFICIENT OF FLUCTUATION OF SPEED
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ENERGY STORED IN A FLYWHEEL
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ENERGY STORED IN A FLYWHEEL
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ENERGY STORED IN A FLYWHEEL
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ENERGY STORED IN A FLYWHEEL
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INTRODUCTION:
In the design of machine mechanisms, it is imperative to know the
magnitudes as well as the directions of forces transmitted from the input tothe output.
The analysis helps in selecting proper sizes of the machine components to
withstand the stresses developed in them.
If proper sizes are not selected, the components may fail during the
machine operation. If components of a machine accelerate, inertia forces are produced due to
their masses.
However, if the magnitude of these forces are small compared to the
externally applied loads, they can be neglected while analyzing the
mechanism. Such an analysis is known as STATIC FORCES ANALYSIS. For Example:- In lifting cranes, the bucket load & the static weight loads
may be quiet high relative to any dynamic loads due to accelerating masses,
& thus static forces analysis is justified.
When the inertia effect due to the mass of the components is also
considered, it is called Dynamic Force Analysis.
STATIC FORCE ANALYSIS
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A body is in static equilibrium, if it remains in its static of rest or motion.
If the body is at rest, it tends to remain at rest & if it is in motion, it tends to keep
the motion.
IN STATIC EQUILIBRIUM:-
(I) The vector sum of all the forces acting on the body is zero.
(II) The vector sum of all the moments about any arbitrary point is zero.
Mathematically,
F = 0 (i)
T = 0 .(ii)
In a Planer system,
Forces can be described by two-dimensional vectors, and therefore,
Fx = 0 (iii)
Fy = 0 .(iv)
Tz = 0 ..(v)
STATIC EQUILIBRIUM
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FREE BODY DIAGRAM
The term body as used here may consist of an entire machine, several connected
parts of a machine, a single part, or portion of a machine part.
A free-body diagram is a sketch or drawing of the body, isolated from the rest of themachine & its surrounding, upon which the forces & moment are shown in action.
It is usually desirable to include on the diagram the known magnitudes & directions
as well as other pertinent information.
Advantages of using free body diagrams:
They make it easier for one to translate words, thoughts & ideas into physicalmodels.
They assist in seeing & understanding all facets of a problem.
They help in planning the approach to the problem.
They make mathematically relations easier to see or find.
They are useful for storing the methods of solutions for future reference. They assist our memory & make it easier to present & explain our work to others.
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ANALYSIS OF STATIC FORCES IN MECHANISM
In analyzing the forces in machines we shall almost always need to separate the
machine into its individual components or subsystems & construct free body
diagram showing the forces that act upon each.
Figure (a) shows a four link mechanism. The free body diagrams of its member 2, 3
& 4 are shown in figure b, c, d respectively. Each member is in equilibrium
individually.
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ANALYSIS OF STATIC FORCES IN MECHANISM
Member 4 is acting upon by three forces F, F34 & F14.
Member 3 is acting upon by two forces F23 & F43.
Member 2 is acting upon by two forces F32 & F12 & a Torque T.
(I) Assume:- forces F on member 4 is known completely. To know the other two
forces acting on this members completely, the direction of one more forces must be
known.
(II) For link 3 is a two-forces member & for its equilibrium F23 & F43 must act along
BC. Thus F34, being equal & opposite to F43, also acts along BC.
(III)For member 4 to be in equilibrium, F14 passes through the intersection of F & F34.
(IV)By drawing a force triangle (F is completely known), magnitude of F14 & F34 can
be known. (figure e).
Now F34 = F43 = F23 = F32
Member 2 will be in equilibrium if F12 is equal, parallel & opposite to F32
And, T = F12 h = F32 h
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INTRODUCTION:
Dynamic forces are associated with accelerating masses. As all machines
have some accelerating parts, dynamics forces are always present when the
machines operates.
For Example:- in case of rotors which rotates at speeds more than 80,000
r.p.m., even slightest eccentricity of the centre of mass from the axis ofrotation produces very high dynamic forces. This may lead to vibrations,
wear, noise or even machine failure.
DYNAMICS FORCES IN MECHANISMS
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DALEMBERTS PRINCIPLE
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EQUIVALENTS OFFSET INERTIA FORCE
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DYNAMICS OF RECIPROCATING PARTS
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DYNAMICS OF RECIPROCATING PARTS
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DYNAMICS OF RECIPROCATING PARTS
DYNAMICS OF RECIPROCATING PARTS
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DYNAMICS OF RECIPROCATING PARTS
CRANK EFFORT
DYNAMICS OF RECIPROCATING PARTS
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DYNAMICS OF RECIPROCATING PARTS
CRANK EFFORT
EQUIVALENT DYNAMICAL SYSTEM
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EQUIVALENT DYNAMICAL SYSTEM
EQUIVALENT DYNAMICAL SYSTEM
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EQUIVALENT DYNAMICAL SYSTEM
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INERTIA FORCE IN RECIPROCATING
ENGINES BY GRAPHICAL METHOD
INERTIA FORCE IN RECIPROCATING
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INERTIA FORCE IN RECIPROCATING
ENGINES BY GRAPHICAL METHOD
INERTIA FORCE IN RECIPROCATING
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INERTIA FORCE IN RECIPROCATING
ENGINES BY GRAPHICAL METHOD
INERTIA FORCE IN RECIPROCATING
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INERTIA FORCE IN RECIPROCATING
ENGINES BY GRAPHICAL METHOD
INERTIA FORCE IN RECIPROCATING
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INERTIA FORCE IN RECIPROCATING
ENGINES BY GRAPHICAL METHOD
INERTIA FORCE IN RECIPROCATING
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INERTIA FORCE IN RECIPROCATING
ENGINES BY GRAPHICAL METHOD
ANALYTICAL METHOD FOR INERTIA
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ANALYTICAL METHOD FOR INERTIA
TORQUE
ANALYTICAL METHOD FOR INERTIA
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ANALYTICAL METHOD FOR INERTIA
TORQUE
ANALYTICAL METHOD FOR INERTIA
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ANALYTICAL METHOD FOR INERTIA
TORQUE
ANALYTICAL METHOD FOR INERTIA
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ANALYTICAL METHOD FOR INERTIA
TORQUE
ANALYTICAL METHOD FOR INERTIA
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ANALYTICAL METHOD FOR INERTIA
TORQUE
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THANK YOU