COURSE INFORMATION COURSE TITLE: ENGINEERING LABORATORY III (BDA 27101) TOPIC 1: SIMPLE PENDULUM 1. INTRODUCTION A small weight (or bob) suspended by a cord forms a simple pendulum. When the pendulum is set swinging, the time (t) swing is found to be constant for a given length of pendulum and is not affected by the weight of the bob or (within limits) by the extent of the arc of swing. This constant time of swing of a simple pendulum forms the basis of time-keeping by some clocks. A pendulum swings under the action of gravity. The force of gravity acting on a freely falling body will give it a steadily increasing speed, or acceleration, which is the same for all bodies, whatever their weight. This acceleration (denoted by g) can be calculated the time of swing of a simple pendulum. 2. OBJECTIVES The objective of this experiment is to show that the time of a simple pendulum depends only on the length of the pendulum, and to determine the value of the force of gravity using a simple pendulum. 3. LEARNING OUTCOMES At the end of this experiment, students should be able to understand the concept of simple pendulum. 4. EXPERIMENTAL THEORY A simple pendulum may be described ideally as a point mass suspended by a massless string from some point about which it is allowed to swing back and forth in a place. A simple pendulum can be approximated by a small metal sphere which has a small radius and a large mass when compared relatively to the length and mass of the light string from which it is suspended. If a pendulum is set in motion so that is swings back and forth, its motion will be periodic. The time that it takes to make one complete oscillation is defined as the period T. Another useful quantity used to describe periodic motion is the frequency of oscillation. The frequency f of the oscillations is the number of oscillations that occur per unit time and is the inverse of the period, f = 1/T. Similarly, the period is the inverse of the frequency, T = l/f. The maximum distance that the mass is displaced from its equilibrium position is defined as the amplitude of the oscillation.
When a simple pendulum is displaced from its equilibrium position, there will be a restoring force that moves the pendulum back towards its equilibrium position. As the motion of the pendulum carries it past the equilibrium position, the restoring force changes its direction so that it is still directed towards the equilibrium position. If the restoring force F is opposite and directly proportional to the displacement x from the equilibrium position, it satisfies the relationship. F = - k x (1) then the motion of the pendulum will be simple harmonic motion and its period can be calculated using the equation for the period of simple harmonic motion T = 2π (2) It can be shown that if the amplitude of the motion is kept small, Equation (2) will be satisfied and the motion of a simple pendulum will be simple harmonic motion, and Equation (2) can be used. Figure 1: Diagram illustrating the restoring force for a simple pendulum. The restoring force for a simple pendulum is supplied by the vector sum of the gravitational force on the mass. mg, and the tension in the string, T. The magnitude of the restoring force depends on the gravitational force and the displacement of the mass from the equilibrium position. Consider Figure 1 where a mass m is suspended by a string of length l and is displaced from its equilibrium position by an angle θ and a distance x along the arc through which the mass moves. The gravitational force can be resolved into two components, one along the radial direction, away from the point of suspension, and one along the arc in the direction that the mass moves. The component of the gravitational force along the arc provides the restoring force F and is given by: F = - mg sin θ (3) BDA27101-Edition III/2011 2
where g is the acceleration of gravity, θ is the angle the pendulum is displaced, and the minus sign indicates that the force is opposite to the displacement. For small amplitudes where θ is small, sinθ can be approximated by θ measured in radians so that Equation (3) can be written as: F = - mg θ. (4) The angle θ in radians is, the arc length divided by the length of the pendulum or the radius of the circle in which the mass moves. The restoring force is then given by: F = - mg (5) and is directly proportional to the displacement x and is in the form of Equation (1) where k =. Substituting this value of k into Equation (2), the period of a simple pendulum can be found by: T = 2π (6) and, T = 2π (7) Therefore, for small amplitudes the period of a simple pendulum depends only on its length and the value of the acceleration due to gravity. 5. ADDITIONAL THEORY BDA27101-Edition III/2011 3
BDA27101-Edition III/2011 4
6. EXPERIMENTAL EQUIPMENTS Table 1: Simple Pendulum Equipment List No. Apparatus Qty. 1 Plumb Bob A 1 2 Plumb Bob B 1 3 Plumb Bob C 1 4 Threaded Rod (Bolt) 1 5 Knurled Nuts 2 6 Measurement Tape 1 7 Protractor (Build in) 1 8 Length of Cord (approx 600mm) 9 Stop Watch (or clock with second hand) 1 7. EXPERIMENTAL PROCEDURES 7.1 PART A 1. The apparatus is shown in Figure 2. 2. Record the weight of each Plumb Bob A, B and C by using digital scales. 3. The simple pendulum is composed of Plum Bob A suspended by a cord which is attached to the threaded rod. 4. The pendulum length (L) should be approximately 140 mm long and clamped between two nuts at the threaded rod. 5. Displace the pendulum about 10 from its equilibrium position and let it swing back and forth. 6. Measure the total time that it takes to make 20 complete oscillations. Repeat the total time measurement for 3 times and record that time in Table 2. 7. Repeat step 5 until step 6 using the angle of 20 and 30. 8. Repeat step 3 until step 7 by using Plumb Bob B and Plumb Bob C. 7.2 PART B 1. Use the Plumb Bob A and set the pendulum length (L) at 100mm. 2. Displace the pendulum about 20 from its equilibrium position and let it swing back and forth. 3. Measure the total time that it takes to make 20 complete oscillations. Repeat the total time measurement for 3 times and record that time in Table 3. BDA27101-Edition III/2011 5
4. Repeat step 1 until step 3 with different pendulum length (L) of 200mm, 300mm, 400mm, 500mm and 600mm. 8. RESULTS AND OBSERVATIONS 1. Complete the Table 2 and Table 3. Record three separate times for 20 swings. 2. Plot the graph of Amplitude versus Periodic Time (t) for each Plumb Bob. 3. Plot the graph of Mass (Plumb Bob) versus Periodic Time (t) for each amplitude tested. 4. Plot the graph of length L versus periodic time (t). 9. DISCUSSIONS 1. Discuss the graphs obtained. BDA27101-Edition III/2011 6
2. Discuss, does the distance the pendulum swings alter its periodic time (t). 3. Discuss, does the periodic timing (t) altered by the weight of pendulum. BDA27101-Edition III/2011 7
4. Discuss, does the periodic timing (t) altered by the amplitude of pendulum. 10. QUESTIONS 1. What are the factors that altered the periodic time for a pendulum? 2. Calculate the average experimental (g) value and compare it with the theoretical (g) value. BDA27101-Edition III/2011 8
3. Explain the difference between simple pendulum and compound pendulum. 11. CONCLUSION Deduce conclusions from the experiment. Please comment on your experimental work in terms of achievement, problems faced throughout the experiment and suggest recommendation for improvements. BDA27101-Edition III/2011 9
BDA27101-Edition III/2011 10
12. EXPERIMENT APPARATUS SET UP THREADED ROD AND NUTS STOPWATCH & MEASURING TAPE PROTRACTOR CORD PANEL BOARD PLUMB BOB A B C Figure 1: Simple Pendulum Apparatus BDA27101-Edition III/2011 11
13. DATA SHEETS TABLE 2: PART A (length of pendulum constant = 140 mm) The time for 20 swings (s) Plumb Bob A Plumb Bob B Plumb Bob C ( kg) ( kg) ( kg) Amplitude ( Degree) Amplitude ( Degree) Amplitude ( Degree) 10 20 30 10 20 30 10 20 30 T1(s) T2(s) T3(s) Average result, (t) TABLE 3: PART B Length of pendulum L, (m) L (m) The time for 20 swings T1 (s) T2 (s) T3 (s) Average results, T(s) Periodic time for one swing ( T/20) Acceleration due gravity, g (m/s 2 ) 0.10 0.20 0.30 0.40 0.50 0,60 * Data sheet must approved by the instructor BDA27101-Edition III/2011 12
14. REFERENCES BDA27101-Edition III/2011 13
COURSE INFORMATION COURSE TITLE: ENGINEERING LABORATORY III (BDA 27101) TOPIC 2: PROJECTILE 1. INTRODUCTION A projectile is a body which is propelled (or thrown) with some initial velocity, and then allowed to be acted upon by the forces of gravity and possible drag. The maximum upward distance reached by the projectile is called the height, the horizontal distance traveled is called the range (or sometimes distance), and the path of the object travel is called its trajectory. If a body is allowed to free-fall under gravity and is acted upon by the drag of air resistance, it reaches a maximum downward velocity known as the terminal velocity. 2. OBJECTIVES The objective of this experiment is to determine the distance traveled by the initial movement of an object throughout a sliding platform and particle free-fall movement to the ground under the action of gravity. 3. LEARNING OUTCOMES At the end of this experiment, students should be able to understand the concept of projectile and its application. 4. EXPERIMENTAL THEORY A r1 O h2 h1 B HII S r2 X X X1 Figure 1 BDA27101-Edition III/2011 14
4.1 Ball movement on the plane: From A to B 1 2 2 At point A, ball has a Potential Energy = I 2 mv. When it reaches point B, the Kinetic Energy depends upon two components of velocities, namely the rotational and translational kinetic energy. 1 2 2 Kinetic Energy = I 2 2 2 2 mu, where, I golf = mr 1 ; I squash = mr 2 1.. (1) 5 3 : angular velocity m : mass of an object r 1 : radius of an object u : velocity at point B 2 2 The sum of energy at point B = mu I mgh2 1 2 Due to the law of conservation of energy,.. (2) The sum of energy at A = The sum of energy at B mgh 1 1 2 2 2 mu I. (3) If no sliding (gelinciran) happened, u r2, where r 2 = OH S OH = 2 2 X X 1 X 2 2 2 r 1. (4) Golf Ball velocity at B, 2gh 1 u g = 2 2 r 1 I 5 r2. (5) Squash Ball velocity at B, 2gh 1 u s = 2 2 r 1 I 3 r2. (6) BDA27101-Edition III/2011 15
4.2 Ball free-fall movement : From B to C AT B, ball will move with a velocity U, Figure 2 a. Calculated time, t when the ball drop at the height of h2 could be obtained from an equation : h 2 2 ut sin 1 2 gt. (7) Differentiate (7) and get v u sin gt. (8) Position C is reached when v = 0, which occurs for or; 0 u sin gt t u sin / g ; g =9.81 m/s. (9) b. Calculated horizontal distance, L when the ball landing at the ground could be obtained from an equation of : L Ut cos. (10) 5. ADDITIONAL THEORY BDA27101-Edition III/2011 16
BDA27101-Edition III/2011 17
6. EXPERIMENTAL EQUIPMENTS Table 1: Projectile Equipment List No. Apparatus Qty. 1 Sliding platform / plane 1 2 Ruler / Measuring Tape 1 3 Golf ball 2 5 Squash ball 1 5 Stop watch 1 6 Non Permanent Marker Pen 1 7. EXPERIMENTAL PROCEDURES 1. Put the sliding platform on the table at the suitable height and measure the angle, θ and the height, h 1 and h 2 (Refer Figure 2). 2. Put the Golf Ball 1 to the platform. 3. Release the ball when the time keeper and distance marker are ready. 4. Start the stop watch when the ball starts to move about from B and keep the time until it touches the ground at point C. 5. Determine the location, point C when the ball landing to the ground. 6. Repeat the procedure several times and determine the distance, L and time, t every time it landing at the ground. Determine the maximum distance, minimum distance, average of the distances and average of the time. 8. OBSERVATIONS 1. Complete the Table 2. 2. From the theory, calculate the value of distance, L and time, t of the golf ball and squash ball. BDA27101-Edition III/2011 18
BDA27101-Edition III/2011 19
9. DISCUSSIONS 1. Discuss the result between Golf Ball 1, Golf Ball 2 and Squash Ball in terms of time and distance obtained by the experiment. 2. What are the factors that affect the result of time and distance? 3. Discuss the differences between the experimental result and the calculation result. BDA27101-Edition III/2011 20
10. QUESTIONS 1. How and when do you think that Moment Inertia (I) of the object affect the results? 2. Explain three (3) applications of Projectile. BDA27101-Edition III/2011 21
3. What happen if we increase the distance between of the platform? 11. CONCLUSION Deduce conclusions from the experiment. Please comment on your experimental work in terms of achievement, problems faced throughout the experiment and suggest recommendation for improvements. BDA27101-Edition III/2011 22
BDA27101-Edition III/2011 23
12. DATA SHEETS TABLE 2: RESULT Distance, L (m) Time (s) Types of ball Experimental L1 L L 2 3 Ave, Calculated, L Experimental t1 t2 3 L t Ave. t Calculated, t Golf 1 Golf 2 Squash The mass of the Golf 1 = kg ; the diameter of the ball = m The mass of the Golf 2 = kg ; the diameter of the ball = m The mass of the Squash = kg ; the diameter of the ball = m Diameter of the sliding platform, X = m ; Distance, h 1 = m The distance between two sliding platform, X1 = m; Distance, h 2 = m Angle, θ = * Data sheet must approved by the instructor BDA27101-Edition III/2011 24
13. REFERENCES BDA27101-Edition III/2011 25
COURSE INFORMATION COURSE TITLE: ENGINEERING LABORATORY III (BDA 27101) TOPIC 3: ENERGY CONSERVATION 1. INTRODUCTION The energy of body is a measure of its capability for doing work. Energy exists in a variety of forms but it cannot be created or destroyed by human. Energy can only be transformed. Conservation of energy states that during the motion the sum of the particle s kinetic and potential energy remains constant. In some cases, kinetic energy can be transformed into potential energy, and vice versa. The conservation of energy equation is used to solve problem involving velocity, displacement and conservative forces. 2. OBJECTIVES The objective of this experiment is to investigate some aspects of potential energy and kinetic energy, and to show that, energy exist and can be transformed stored and given back. 3. LEARNING OUTCOMES At the end of this experiment, students should be able to understand the concept of conservation of energy and its application. 4. EXPERIMENTAL THEORY Energy exists in a variety of forms but it cannot be created or destroyed. Energy can only be transformed. When an engineer refers to losses in energy he is only applying that it is not doing useful work. Because there are losses in any machine the useful energy given out is always less than the energy put in. In other words: Input Energy = Useful Energy + Useless Energy, Or to put it more technically: Input Energy = Output Energy + losses There are two types of energy which are called POTENTIAL and KINETIC. POTENTIAL ENERGY (PE) is the amount of WORK AVAILABLE in a given body at rest. A weight raised above some datum level is said to possess potential BDA27101-Edition III/2011 26
energy, since it is able to do work in falling to the datum level. KINETIC ENERGY (KE) is the amount of WORK POSSESSED or stored by a MOVING body. If the weight described above is allowed to fall freely to the datum level all the potential energy will be transformed to an equal quantity of Kinetic energy provided the falling weight encounters no resistance. WORK = Force x distance moved. (1) Therefore if a weight (W) is raised through the distance (H1) the work available is equal to W x H1, and this amount of energy was given up as the weight fell. See Fig. 1. Potential Energy (Initial) = W x H1. (2) Where, W = weigh and h = height of body from the datum During the test weight (W) ascended to the height (H2). At this final position it again possesses Potential Energy. Therefore: Potential Energy (Initial) = W x H2. (3) Losses in PE = WH1 WH2. (4) 5. ADDITIONAL THEORY BDA27101-Edition III/2011 27
BDA27101-Edition III/2011 28
6. EXPERIMENTAL EQUIPMENTS Table 1: Energy Conservation Equipment List No. Apparatus Qty. 1 Panel board 1 2 Flywheel assembly with cord 60 cm long attached 1 3 Nuts 2 4 Weight hook [0.1N] 1 5 Set of weights 1 7. EXPERIMENTAL PROCEDURES 1. Set up the panel board diagram as shown in Figure 2. Tighten the flywheel to the top center of the panel board with nuts. 2. Determine the suitable height for h 1 ~ 400 mm. Record the value of h 1. Ensure the lowest position for weight hook exactly level with the bottom edge of the panel. 3. Place a load of 0.7 N to the weight hook. Record the total load, W 4. Then, release the flywheel from the height, h 1. Ensure there is no obstructed during its fall. Wait until the weight reaches the lowest position. 5. While flywheel lifts the load, be careful and mark the level of h 2 at the panel board. 6. Measure the maximum height and record h 2. 7. Repeat procedure 3 to 6 using different load, 1.0N, 1.5N, 2.0N, 2.5N and 3.0N. 8. OBSERVATIONS 1. Complete the Table 2. Calculate Potential Energy and Energy Losses BDA27101-Edition III/2011 29
2. Plot a graph of Load, W against energy losses (Wh 1 -Wh 2 ). 3. Plot a graph of Load, W against height, h 2 9. DISCUSSIONS 1. Discuss the graph of Load, W against energy losses (Wh 1 -Wh 2 ). 2. Discuss the graph of Load, W against height, h 2. BDA27101-Edition III/2011 30
3. Judging from H1 and H2, approximately what proportion of the energy had transformed, stored and given back? Discuss. 4. Do the losses increase as the load increases? Discuss. BDA27101-Edition III/2011 31
10. QUESTIONS 1. Suggest some cause for the losses in Potential Energy. 2. Which one most contributing for storing and giving back the energy, the flywheel or the weight? Discuss. 3. Write the energy equation that relates work, kinetic energy and potential energy. BDA27101-Edition III/2011 32
11. CONCLUSION Deduce conclusions from the experiment. Please comment on your experimental work in terms of achievement, problems faced throughout the experiment and suggest recommendation for improvements. BDA27101-Edition III/2011 33
BDA27101-Edition III/2011 34
W W In practical (Refer Figure 1) Total energy in Total energy out energy loss Potential energy ()() initial Potential energy final energy loss Energy loss Potential energy ()() initial potential energy final h 2 h 1 W Figure 1: Energy Losses Diagram Clamp Pad Starting Position Approximate Finishing Line h 2 h 1 Lowest Position Figure 2: Energy Conservation Apparatus Setup. BDA27101-Edition III/2011 35
12. DATA SHEETS TABLE 2: RESULT Weight load Height Potential Energy Energy loss Initial Final Initial Final W h 1 h 2 P.E 1 =Wh 1 P.E 2 =Wh 2 Wh 1 - Wh 2 (N) (m) (m) (Nm) (Nm) (Nm) 0.8 1.0 1.5 2.0 2.5 3.0 * Data sheet must approved by the instructor 13. REFERENCES BDA27101-Edition III/2011 36
COURSE INFORMATION COURSE TITLE: ENGINEERING LABORATORY III (BDA 27101) TOPIC 4: CRANK MOTION 1. INTRODUCTION In certain types of machines it is necessary to convert straight line (or linear) motion into circular motion. The most common example is the reciprocating engine, whether it is a steam or internal combustion engine. Energy is produced in the cylinder and the piston moves backwards and forwards (or up and down). The piston transmits its motion via the crosshead and connecting rod, to a point called the crankpin which is fixed to an arm on the crankshaft. The crankshaft is free to revolve about a fixed centre so that the crankpin rotates at radius (r); this radius (r) being equal to half the stroke of the piston. By the link mechanism (called the crank mechanism) the linear movement of the piston is converted into circular motion at the crankshaft. 2. OBJECTIVES The objectives of this experiment are to investigate the characteristics of crank mechanism by constructing a turning moment graph from experimental results and comparing the experimental graph with the theoretical graph. 3. LEARNING OUTCOMES At the end of this experiment, students should be able to understand the concept of crank motion and its application. 4. EXPERIMENTAL THEORY The driving force, called the Turning Moment (TM) is continually changing during each revolution of the crank. This is partly due to the fact that the force (P) produced at the piston does NOT remain constant, and partly due to the nature of the link mechanism. In this experiment, the piston force (P) is ASSUMED to be constant so that the effect of link mechanism may be considered in detail without further complication. The Turning Moment (TM) at any instant is equal to F x d, but both (F) and (d) vary as the crank revolves. Turning Moment (TM) = R x E = F x d (1) Where, R ~ flywheel radius = 47.5 mm and E ~ Turning Force BDA27101-Edition III/2011 37
Therefore, TM = 47.5 x E and TM = F x d (2) Where, F ~ Force at the cord d ~ distance between the line of force (F) and the center of rotation, measured at right angles to the line of force (F) This experiment will show the rate at which Turning Moment (TM) varies and that twice during each revolution the (TM) is zero and twice it will reach a maximum. Turning Moment (TM) graph obtained as Figure 1. Figure 1: TM Graph 5. ADDITIONAL THEORY BDA27101-Edition III/2011 38
BDA27101-Edition III/2011 39
6. EXPERIMENTAL EQUIPMENTS Table 1: Simple Pendulum Equipment List No. Apparatus Qty. 1 Crank Assembly (EX35) 1 2 Adjustable Hook 1 3 10N Spring Balance (P8) 1 4 Adjustable Pulley 1 5 Knurled Nuts 4 6 Weight Hook 1 7 Set of Weights (P) 1 7. EXPERIMENTAL PROCEDURES 1. Set up panel board as shown in Figure 3. 2. Place a weight of 10N on the weight hook, making a total weight 10.1N. The weight on the hook will pull the crank out flat, a position generally called dead center which is angle = 0. 3. Hang the 10N spring balance with adjustable hook. Ensure the value of spring balance, E = 0. 4. Then, shift the adjustable hook until 0 angle = 10. Fix the piston and record the spring balance reading, E shown on the spring balance scale. 5. Repeat step 4 and each time increasing the angle 0 = 10. The final angle is 170 from zero. 6. Fill in the table. 8. OBSERVATIONS 1. Complete the Table 2. Calculate experimental Turning Moment (TM). BDA27101-Edition III/2011 40
2. Plot a graph of turning moment, TM against crank angle (θ) revolution for both theoretical and experimental results. 3. On the same graph, plot TM maximum values against crank angle (θ) for both theoretical and experimental results. 9. DISCUSSIONS 1. Discuss the graphs obtained. 2. Compare results between theoretical Turning Moment and experimental results. BDA27101-Edition III/2011 41
3. Discuss, at what angle (θ) did the Turning Moment reach maximum? 4. How many maximum TM values are reached during each revolution of the crank? Discuss. BDA27101-Edition III/2011 42
10. QUESTIONS 1. What are the factors that altered the results of Turning Moment (TM)? 2. Give two (2) examples of Crank Mechanism application. Explain how its work. BDA27101-Edition III/2011 43
11. CONCLUSION Deduce conclusions from the experiment. Please comment on your experimental work in terms of achievement, problems faced throughout the experiment and suggest recommendation for improvements. BDA27101-Edition III/2011 44
12. EXPERIMENTAL DIAGRAM E R R = 47.5mm r = 25.0 mm L = 95.0 mm Stroke = 2r r Q d θ F 0 L α F P P = 10.1 N Q F α Forces on Crosshead Figure 2: Crank Mechanism Diagram Figure 3: Crank Mechanism Apparatus Setup BDA27101-Edition III/2011 45
13. DATA SHEET TABLE 2: RESULTS Crank Angle Centrifugal Force Experimental Turning Moment, TM Theoretical θ (degree) E (N) 47.5 x E(Nmm) (Nmm) 0 0 0 0 10 55,2 20 107,8 30 155,3 40 195,5 50 226,8 60 248,2 70 259,3 80 260,4 90 252,5 100 236,9 110 215,2 120 189,1 130 160.0 140 129,1 150 97,2 160 64,9 170 32,5 180 0 0 0 * Data sheet must approved by the instructor BDA27101-Edition III/2011 46
14. REFERENCES BDA27101-Edition III/2011 47
COURSE INFORMATION COURSE TITLE: ENGINEERING LABORATORY III (BDA 27101) TOPIC 5: UNIVERSAL COUPLING 1. INTRODUCTION A flexible coupling or universal joint is frequently used to link with two shafts and transmit circular motion from the other. Indeed continuous circular motion is perhaps the single largest thing that mankind produces in the world with the available energy. A universal joint is simply and combination of machine elements which transmit rotation from one axis to another. 2. OBJECTIVES The objective of this experiment is to investigate the effect of introducing universal couplings to a simple drive shaft and to check the uniformity of angular movement between the driving and the driven end of the shaft in a straight line assembly and then again with an angular transmission. A further objective is to repeat these tests with the couplings set up at incorrect position assembly to see how this interferes with uniform angular transmission. 3. LEARNING OUTCOMES At the end of this experiment, students should be able to understand the operating principles and application of the universal coupling. 4. EXPERIMENTAL THEORY Shafts are used to transmit rotary motion and in most cases these shafts rotate in bearings set in a straight line. However, there are cases where the shaft cannot be straight and it has to be operated through an angle X, refer Figure 1. A good example in common use is the shaft which transmit power from a motor car engine through its gearbox to the back axle to drive the rear wheels. Here the shaft is generally at an angle and the operation is further complicated by the fact that the angle varies when the motor car runs over bumps in the road. Such condition can be satisfied by the use of universal couplings as shown at A and C in Figure 1. For uniform power transmission the design and assembly of the two couplings must be carefully considered. BDA27101-Edition III/2011 48
Figure 1: Universal Coupling Diagram 5. ADDITIONAL THEORY BDA27101-Edition III/2011 49
BDA27101-Edition III/2011 50
6. EXPERIMENTAL EQUIPMENTS Table 1 : Universal Coupling Equipment List No. Apparatus Qty. 1 Universal Joint Assembly 1 2 Knurled Screws 2 3 Knurled Nuts 2 7. EXPERIMENTAL PROCEDURES 7.1 TEST 1 1. Joint assembly to the panel board in a convenient position. 2. Set right coupling so that the shaft is in a straight line. Refer to A-B position in Figure 1. 3. Set the left and right coupling position with tighten the screws D1, D2, D3 and D4. [Please refer to Figure 2 for the correct couplings and screws position]. 4. Now set the right and left coupling scales as 0 degrees. 5. Move the left hand scale at 20 increments and note the reading on the right hand scale. 6. Repeat this at 20 increments until 180 is reached and recorded. Figure 2: Coupling position for Test 1 and Test 3 (top view) 7.2 TEST 2 1. Set right coupling so that the shaft is in a straight line. Refer to A-B position in Figure 1. 2. Set the left and right coupling position with tighten the screws D1, D2, D3 and D4. [Please refer to Figure 3 for the correct couplings and screws position] BDA27101-Edition III/2011 51
3. Repeat procedure (4) until (6) in test 1. 7.3 TEST 3 Figure 3 : Coupling position for Test 2 and Test 4 (top view) 1. Remove the right coupling assembly and move it to Position C as shown in Figure 1. 2. Set the left and right coupling position with tighten the screws D1, D2, D3 and D4. [Please refer to Figure 2 for the correct couplings and screws position]. 3. Repeat procedure (4) until (6) in test 1. 7.4 TEST 4 1. Still in Position A-C as shown in Figure 1. 2. Set the left and right coupling position with tighten the screws D1, D2, D3 and D4. [Please refer to Figure 3 for the correct couplings and screws position]. 3. Repeat procedure (4) until (6) in test 1. 8. OBSERVATIONS 1. Complete the Table 2. 2. Plot the graph Right Hand Dial against Left Hand Dial Result for Test 1, Test 2, Test3 and Test 4. 9. DISCUSSIONS 1. Discuss the graphs obtained. BDA27101-Edition III/2011 52
2. Discuss about shaft and coupling in the straight line assembly. 3. Discuss about shaft and coupling in angular assembly. BDA27101-Edition III/2011 53
10. QUESTIONS 1. Give two (2) example of Universal Couplings application in mechanical engineering. 2. How Universal Coupling works in both example in question 1. BDA27101-Edition III/2011 54
11. CONCLUSION Deduce conclusions from the experiment. Please comment on your experimental work in terms of achievement, problems faced throughout the experiment and suggest recommendation for improvements. BDA27101-Edition III/2011 55
12. DATA SHEETS TABLE 2: RESULTS TEST 1 TEST 2 TEST 3 TEST 4 Coupling Coupling Coupling Coupling Left Right Left Right Left Right Left Right 0 0 0 0 20 20 20 20 40 40 40 40 60 60 60 60 80 80 80 80 100 100 100 100 120 120 120 120 140 140 140 140 160 160 160 160 180 180 180 180 * Data sheet must approved by the instructor 13. REFERENCES BDA27101-Edition III/2011 56
REFERENCES CES DYNAMICS: 1. Bedford, A. and Fowler, W., 2008. Engineering Mechanics-Dynamics, 5 th Edition, Pearson Prentice Hall. 2. Soutas-Little, R.W., Inman, D. J. and Balint, D.S., 2008. Engineering Mechanics: Dynamics, Thomson Learning. 3. Beer, F.P., Johnston, E. R. and Flori, R.E., 2007. Mechanics for Engineers - Dynamics, 5th Edition, Mc Graw Hill. 4. Beer, F.P, Calusen, E.W and Johnson, E.R, 2007. Vector Mechanics for Engineers - Dynamics, 8 th SI Edition, McGraw Hill. 5. Hibbeler, R.C., 2007. Engineering Mechanics Dynamics, 11 th SI Edition, Pearson Prentice Hall. 6. Meriam, J.L. and Kraige, L. G., 2003, Engineering Mechanics: Dynamics, 5 th Edition, John Wiley & Sons, Inc. BDA27101-Edition III/2011 57
APPENDICES DEPARTMENT OF ENGINEERING MECHANICS Kod M/Pelajaran/ Subject Code Kod & Tajuk Ujikaji/ Code & Title of Experiment Kod Kursus/ Course Code Kumpulan/Group Nama Pelajar/Name of Student Lecturer/Instructor/Tutor s Name Nama Ahli Kumpulan/ Group Members DYNAMICS LABORATORY LAPORAN MAKMAL/LABORATORY REPORT 1. 2. No. Matrik ENGINEERING LABORATORY III Penilaian / Assesment BDA 27101 Seksyen /Section No. K.P / I.C No. No. Matrik 1. Teori / Theory 10 % 2. 3. 4. 5. Tarikh Ujikaji / Date of Experiment Tarikh Hantar / Date of Submission Keputusan / Results Pemerhatian /Observation Pengiraan / Calculation Perbincangan / Discussions Kesimpulan / Conclusion Rujukan / References 15 % 20 % 10 % 25 % 15 % 5 % JUMLAH / TOTAL 100% ULASAN PEMERIKSA/COMMENTS COP DITERIMA/APPROVED STAMP