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Mechanical VibrationsMDP 0515
INTRODUCTION
Assiut University
Eng. AHMED ABD EL-ALYM AMEN
Outlines
Introduction
Vibrations in our Life.
Mechanical Vibrations & Modeling of
Dynamic Systems.
Vibration Terminologies.
Course Contents.
2
Introduction
Introduction
4
Lectures: 1 lecture per week (2 credit hrs. )
Reference: Mechanical Vibrations (5th Edition) by Singiresu S. Rao.
Prerequisites:
1.Statics and Dynamics
2.Mechanics of materials
3.Differential Equations
Year work: (60% of total marks)
1. Projects: 1 project (20%)
2. Attendance: (10%)
3. Mid-term exam: (30%)
Final exam: (40% of total marks)
5
Introduction
StaticsWho Cares?
DynamicsKinematics
Vibrations in our Life
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Vibrations in all of our life, as we can say we can not live without
vibrations.
Hearing
Walking
Vision
Lungs oscillation
Heartbeat
Earthquakes
Snoring
You can not live without it, and some times you
can not live with it.
Vibrations in our Life
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Vibrations in machinery:
Identification to the system
1. Natural Frequency
2. Vibration Mode/ Vibration Shape
3. Damping
Vibrations in our Life
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Vibrations in Transportation
Vibrations in Recreation
Vibrations in Automobiles
Vibrations in our Life
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Vibrations in our Life
Friend Foe
- Conveyors
- Drills
- Washing Machine
- Mechanical Shaker
- Medical Applications-
Massagers
- Resonance
- Turbine Machines,
Pumps.
- Machine tools.
- Noise.
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Vibrations in our Life
Friend Foe
- Conveyors
- Drills
- Washing Machine
- Mechanical Shaker
- Medical Applications-
Massagers
- Resonance
- Turbine Machines,
Pumps.
- Machine tools.
- Noise.
12
Vibrations in our Life
Mechanical Vibrations&
Modeling of Dynamic Systems
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Vibrations of dynamic systems:
Consists of:
1. Mass
1. Spring.
1. Damper.
Mechanical Vibrations
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Vibrations Analysis
Vibration Analysis Procedure
Step 1: Mathematical Modelling
Step 2: Derivation of Governing Equations
Step 3: Solution of the Governing Equations
Step 4: Interpretation of the Results
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Modeling of Dynamic Systems
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Modeling of Dynamic Systems
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Modeling of Dynamic Systems
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Modeling of Dynamic Systems
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Modeling of Dynamic Systems
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Modeling of Dynamic Systems
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Modeling of Dynamic Systems
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Modeling of Dynamic Systems
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Modeling of Dynamic Systems
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Modeling of Dynamic Systems
Vibration Terminologies
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Vibration: A magnitude (force, displacement, or acceleration) which
oscillates about some specified reference where the magnitude of the force,
displacement, or acceleration is alternately smaller and greater than the
reference.
periodic motion: motion repeated in equal intervals of time.
Harmonic Motion: the simplest form of periodic motion, in which the
acceleration commensurate with the displacement in reverse
Vibration Terminologies
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Cycle|: The motion completed during the period
Vibration Terminologies
Natural frequency: the frequency with which it oscillates without
external forces is known as its natural frequency.
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Vibration Terminologies
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Vibration Terminologies
Course Contents
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1. Vibration of single degree of freedom systems (free, damped, forced)
2. Vibration isolation, Vibration of two degree of freedom systems (free,
forced),
3. Vibration absorber,
4. Torsional vibration (free, forced),
5. Dynamic stresses,
6. and Equivalent torsional systems: Geared system, Crank system,
7. Vibration of multi-degree of freedom systems (free. Forced),
8. Critical speeds of shafts: Shafts with lumped masses, Shafts with
distributed masses
Course Contents
33
Modeling of Dynamic Systems
Draw the mathematical model for the system
shown by Four alternatives:
1. Single Degree of freedom
2. Two Degrees of freedom
3. Three Degrees of freedom
4. Four Degree of freedom
11/12/2014
