ME6511– DYNAMICS LABORATORY LIST OF EXPERIMENTS 1. Free Transverse Vibration – I – Determination of Natural Frequency 2. Cam Analysis – Cam Profile and Jump-speed Characteristics 3. Free Transverse Vibration – II – Determination of Natural Frequency 4. Free Vibration of Spring Mass System – Determination of Natural Frequency 5. Compound Pendulum – Determination of Radius of Gyration and Moment of Inertia 6. Bifilar Suspension – Determination of Radius of Gyration and Moment of Inertia 7. Trifilar Suspension – Determination of Radius of Gyration and Moment of Inertia 8. Whirling of Shaft – Determination of Critical Speed 9. Balancing of Rotating Masses 10. Determination of Gyroscopic Couple 11. Turn Table 12. Hartnell Governor 13. Free Vibration of Spring Mass System – Determination of Natural Frequency Beyond the Syllabus 14. Speed Ratio of Epi-cyclic Gear Train 15. Speed Ratio of Worm and Worm Wheel
EX NO:1: Aim: TRANSVERSE VIBRATION - I To find the natural frequency of transverse vibration of the cantilever beam. Apparatus required: Displacement measuring system (strain gauge) and Weights Description: Strain gauge is bound on the beam in the form of a bridge. One end of the beam is fixed and the other end is hanging free for keeping the weights to find the natural frequency while applying the load on the beam. This displacement causes strain gauge bridge to give the output in millivolts. Reading of the digital indicator will be in mm. Formulae used: 1. Natural frequency = 1/2 (g/ ) Hz Where g = acceleration due to gravity in m/s2 and 2. Theoretical deflection = Wl3/3EI Where, W = applied load in Newton, L = length of the beam in mm E= young‟s modules of material in N/mm2, I= moment of inertia in mm4 =bh3/12 3. Experimental stiffness = W/ N-mm and = deflection in m.
Procedure: 1. Connect the sensors to instrument using connection cable. 2. Plug the main cord to 230v/ 50hz supply 3. Switch on the instrument 4. Keep the switch in the read position and turn the potentiometer till displays reads “0” 5. Keep the switch at cal position and turn the potentiometer till display reads 5 6. Keep the switch again in read position and ensure at the display shows “0” 7. Apply the load gradually in grams 8. Read the deflection in mm Graph: Draw the characteristics curves of load vs displacement, natural frequency Draw the characteristics curves of displacement vs natural frequency Observation: Cantilever beam dimensions: Length=30cm, Breadth=6.5cm and Height=0.4cm Tabulation: Sl. Applied No. mass m (kg) Deflection (mm) Theoretical Experimental deflection Stiffness k (N/mm) T (mm) Theoretical Stiffness k (N/mm) Natural frequency fn (Hz) Result: The natural frequency of transverse vibration of the cantilever beam were determined and tabulated.
EX NO:2 CAM ANALYSIS Aim: To study the profile of given can using cam analysis system and to draw the displacement diagram for the follower and the cam profile. Also to study the jump-speed characteristics of the cam & follower mechanism. Apparatus required: Cam analysis system and Dial gauge Description: A cam is a machine element such as a cylinder or any other solid with a surface of contact so designed as to give a predetermined motion to another element called the follower.A cam is a rotating body importing oscillating motor to the follower. All cam mechanisms are composed of at least there links viz: 1.Cam, 2. Follower and 3. Frame which guides follower and cam. Specification : Diameter of base circle =150mm, Lift = 18mm, Diameter of cam shaft = 25mm Diameter of follower shaft = 20 mm, Diameter of roller = 32mm, Dwell period = 180 Type of follower motion = SHM (during ascent & descent) Procedure: Cam analysis system consists of cam roller follower, pull rod and guide of pull rod. 1. Set the cam at 0° and note down the projected length of the pull rod 2. Rotate the can through 10° and note down the projected length of the pull rod above the guide 3. Calculate the lift by subtracting each reading with the initial reading. Jump-speed: 1. The cam is run at gradually increasing speeds, and the speed at which the follower jumps off is observed. 2. This jump-speed is observed for different loads on the follower. Graph: Displacement diagram and also the cam profile is drawn using a polar graph chart. The Force Vs Jump-speed curve is drawn. Tabulation: 1.Cam profile Sl. Angle of Lift in mm No. rotation (degrees) Result: 2. Jump-speed. Lift + base circle Load on the radius (mm) Follower, F (N) Jump-speed N (RPM)