Rajalakshmi engineering college Department of mechanical engineering Subject: ME1301 - Dynamics of Machinery Class: V Semester Mechanical A & B
NOTES ON LESSON UNIT – I - Force Analysis
Basic Concepts and Principles Newton’s Law First Law Second Law Third Law Types of force Analysis Static Equilibrium of Various members ♦ Equilibrium of members with two forces ♦ Equilibrium of members with three forces ♦ Equilibrium of members with two forces and torque ♦ Equilibrium of members with two couples. ♦ Equilibrium of members with four forces. Principle of Super Position Free Body Diagram. Static Force Analysis of Mechanisms by superposition principle. D’Alemberts Principle Dynamic Analysis of Four bar Mechanism Dynamic Analysis of Reciprocating engines. Inertia force and torque analysis by neglecting weight of connecting rod. Velocity and acceleration of piston. Angular velocity and Angular acceleration of connecting rod. Force and Torque Analysis in reciprocating engine neglecting the weight of connecting rod. Equivalent Dynamical System Determination of two masses of equivalent dynamical system Correction Couple to be applied to make two mass system dynamically equivalent Inertia force and torque analysis in reciprocating engines by considering the weight of connecting rod.
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TURNING MOMENT DIAGRAM AND FLYWHEEL Turning Moment diagram for various types of engine Single cylinder double acting engine. Four Stroke IC Engine. Multi Cylinder Engine. Fluctuation of Energy Fluctuation of Speed. Determination of Maximum fluctuation of energy. Determination of Work Done per cycle. Coefficient of fluctuation of speed. Energy stored in flywheel, Flywheel in punching press. CAM DYNAMICS Rigid and elastic body cam system. Mathematical Model of rigid body cam system. Mathematical Model of Elastic cam system. Analysis of eccentric cam Problems on Cam –follower system. Unbalance, Spring Surge, Wind up.
UNIT – II BALANCING
Balancing of rotating masses. Static balancing Dynamic balancing Various cases of balancing of rotating masses ♦ Balancing of a single rotating mass by single mass rotating in the same plane. ♦ Balancing of a single rotating mass by two masses rotating in the different plane. ♦ Balancing of a several masses rotating in different planes. Balancing of Reciprocating masses. Shaking Forces and couples. Primary and secondary unbalanced forces of reciprocating parts. Balancing of single cylinder engine Partial balancing of Locomotives. Effect of unbalanced primary force along the line of stroke Variation of Tractive force. Swaying Couple. Hammer blow. Balancing of Inline engines. Balancing of radial engines. 2
Balancing of V-engines. Balancing of linkages.
UNIT –III FREE VIBRATIONS.
Basic elements of lumping parameter. Causes of vibration. Effects of vibration. Methods of reduction of vibration. Types of vibratory motion.. Types of vibration. Degrees of freedom.
Longitudinal Vibration:
Free undamped longitudinal vibrations. Natural frequency of free undamped longitudinal vibration. Effect of inertia in longitudinal vibration. Equivalent stiffness of spring. Damping Types of damping, Damping Coefficient, Equivalent damping coefficient. Damped Vibration. Free longitudinal vibrations Natural frequency of free damped vibration. Degree of dampness Damping factor. Critical damping coefficient. Logarithmic decrement.
Transverse Vibration.
Natural frequency of free transverse vibration- single load. Natural frequency of free transverse vibrations – Multiple loading. Whirling of shaft. Torsional Vibration. Natural frequency of free torsional vibrations of a single rotor system. Equivalent torsional stiffness of shaft. Torsionally equivalent shaft. Free torsional vibration of geared system.
UNIT- IV FORCED VIBRATION Basics of forced vibration- Forcing function. Types of forced vibration. Damped forced vibration with harmonic function. Forced vibration due to rotating unbalance.
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Forced vibration due to reciprocating unbalance. Forced vibration due to support motion.. Vibration Isolation and Transmissibility.
UNIT- V MECHANISM FOR CONTROL Governor Introduction. Differences between flywheel and governor. Study of centrifugal governor Principle of Working, Characteristics, Terms used. Study of pendulum type governor- Watt Governor. Study of loaded type governor Gravity controlled governor- Porter governor, Proell Governor. Spring Controlled Governor – Hartnell Governor, Hartung Governor, Sensitiveness of governor. Stability of governor Isochronous governor Hunting Governor. Effort of governor. Power of governor Controlling force. Coefficient of insensitiveness. Gyroscope and its applications
Active and reactive forces. Angular velocity. Precessional angular motion. Gyroscopic couple. Effect of gyroscopic couple on airplane Effect of gyroscopic couple on ship. Stability of an automobile.
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