Experiment N0-02

Experiment No-01

Object: To determine the hardness of the given specimen using Rockwell Hardness Testing Machine.

Experimental set up/Equipment/Apparatus/Tools Rockwell hardness testing machine, specimen of high speed steel or alloy steel.

Theory and application: The hardness of a material is its resistance to penetration under a localized pressure or resistance to abrasion. Hardness tests provide an accurate, rapid and economical way of determining the resistance of material to deformation. There are three general types of hardness measurements depending open the manner in which the test is conducted.(i) Scratch hardness measurement (ii) Rebound hardness measurement and (ii) Indentation hardness measurement.In scratch hardness method the material are rated on their ability to scratch one another. In rebound hardness measurement, a standard body is usually dropped on to the material surface and the hardness is measured in terms of the height of its rebound. The general means of judging the hardness is measuring the resistance of material to indentation. The indenter is usually a ball, cone or pyramid of a material much harder that the being tested. In indentation test a load is applied by pressing the indenter at right angles to the surface being tested. The hardness of the material depends on the resistance which it exerts. During a small amount of yielding or plastic straining.The test consists of forcing an indenter of standard cone or ball in to the surface of a test piece and measuring the permanent increase in depth of indentation of this indenter under specified condition. From this Rockwell hardness is deduced. The ball (B) is used for soft materials (e.g. mild steel, cast iron, aluminium, etc.)And the cone (C) for hard cones (e.g. high carbon steel, high speed steel etc.)

Experimental Procedure: it is performed in the following sequential manner. Insert indenter on to the machine. Make the specimen surface clean by removing the dust, dirt, oil and grease etc. Select 150kg load. Make contact between the specimen surface and the ball by rotating the jack adjusting wheel till needle touch red mark. Pull the load release lever and wait for minimum 30seconds. The load will automatically apply gradually. Note the hardness reading Repeat the entire operation, three times.

Observation:

HardnessMean Hardness(HRC)

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Result:Rockwell Hardness of given specimen =-------------------HRC

Precautions and sources of error Ensure proper indenter is fixed on the machine. Use V-Block for round jobs Select proper load Move wheel gradually & slowly. Do not cross the red mark on the smaller dial. Ensure surface is smooth & polished.Related short questions:What is hardness?How many types of method to check hardness of materials.How many scales in Rockwell hardness.B and C scale where use?Can we check soft materials hardness in this method?

University of Petroleum & energy studies Dehradun 02Experiment N0-02

1. Object: To determine the hardness of the given specimen using Brinell Hardness Testing Machine.

2. Experimental set up/Equipment/Apparatus/Toolsi. Brinell hardness Testing Machine.ii. Specimen of mild steel/Cast iron/non ferrous metals.iii. Optical microscope.3. Theory and application:

4. Formula used: BHN =

B.H.N = WhereP is applied load in kgfD is dia of balld is dia of indentation5. Experimental Procedure: It is performed in the following sequential manner.1- Insert indenter on to the machine.2- Make the specimen surface clean by removing the dust, dirt, oil and grease etc.3- Select 250 Kg load.4- Make contact between the specimen surface and the ball by rotating the Jack adjusting wheel till needle touch red mark.5- Pull the load release lever and wait for minimum 30 seconds. The load will automatically apply gradually.6- Unload by pulling the load lever back to normal position.7- Remove the specimen from the support table, and locate the indentation so made.8- View the indentation through optical microscope and measure its diameters by micrometer fitted on microscope, or by any other available means.9- Take two readings of the indent right angles to each other.10- Repeat the entire operation, three times.6. Observations:Following observations are recorded from a test on steel specimen using a hardened steel ball as indenter. The diameter of indentation is viewed by an optical microscope of magnification 10X.

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Total load P = ------------- KgDiameter of ball D = ------------mm

S no.Diameter of indentation(mm)dBHNMean BNN

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7. Calculations: The Brinell hardness is calculated as follows.

B.H.N = WhereP is applied load in kgfD is dia of balld is dia of indentation

8. Result: BHN of steel specimen is -------- Although the BHN is expressed in kg/mm2 but this unit is generally not written.

9. Precautions and sources of error Ensure proper indenter is fixed on the machine. Use V-Block for round job Select proper load Note the diameter of the indent carefully. Do not cross the red mark on the smaller dial. Ensure surface is smooth & polished

10. Related short questions: What is the significance of hardness in general life give example? What is difference between Rockwell and Brinel Hardness? Which types of materials you can check hardness shoft or hard? Which type indenter use in Brinel hardness? If steel ball not Hard then what will be happen? How you can make surface scratch proof?

University of Petroleum & energy studies Dehradun 04

experiment No-03

1. Object: To find the spring constant and Modulus of Rigidity of a given spring using spring testing Machine.2. Experimental set up/Equipment/Apparatus/Tools -Spring testing Machine/ spring/ Vernier caliper/out side caliper/ Micrometer3. Theory and application: Spring index K (or spring stiffness) is defined as the load W that causes unit deflection in the spring. This deflection is in the form of contraction in a compression spring and in the form of extension form in tension spring. Thus spring index or stiffness K= Spring index is an important parameter in selection of spring for a particular use. It is expressed in N/mm or Kg/mm. The nature of load vs. deflection curve decides whether the behavior of spring is linear or non-linear. Mostly close coiled helical springs have linear nature.4. Formula used: Modulus of Rigidity, C= N/mm2 Stiffness K= 5. Experimental Procedure:1- By using the vernier caliper/Micrometer measure the diameter of the wire of the spring.2- By using the vernier caliper measure the diameter of spring coil.3- Count the number of turns of the spring.4- Measure the original length of the spring5- Insert the spring in the spring testing machine and load the spring by suitable weight by opening the control valve slightly and slowly.6- Note the corresponding axial deflection in tension or compression.7- Increase the load and take the corresponding axial deflection reading.8- Repeat the procedure for at least four times.9- Open the release valve slowly after the experiment.6. Observation: Diameter of the spring wire (mean of the three readings), d = --------mmDiameter of the spring coil (mean of the readings), D =-----------mmMean coil diameter, Dm =D-d or D+d = -----------mmNumber of Turns n = -------- University of Petroleum & energy studies Dehradun 05

S.noLoad W (in Kg)Load W (in Newton)Deflection(cm) Deflection(mm) Stiffness, K= W/ N/mm

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7. Calculations:Stiffness K = N/mmModulus of Rigidity, C= N/mm28. Result: Stiffness of given spring is = ----------- N/mm Modulus of rigidity of given spring is = ------ N/mm29. Precautions and sources of error Place the spring centrally and accordingly whether its tension or compression spring. Take the mean diameter of the coil as the average of external and internal coil diameter. Do not load the spring beyond the elastic limit.10- Related short questions: What is Stiffness? What is modulus of rigidity? What is the significance of modulus of rigidity? Which type of spring you have checked? Tell the name of different types of spring? Give the example where springs are useful in general life.

University of Petroleum & energy studies Dehradun 06 Experiment No-041. OBJECT: to conduct the tensile test on a UTM and determine the ultimate tensile strength and percentage elongation for a steel specimen.2. Experimental set up/Equipment/Apparatus/Tools Universal Testing Machine Mild steel specimen Vernier caliper/out side caliper3. Theory and application: Various machine and structural components are subjected to tensile loading in numerous operations. For safe design of these components, their ultimate tensile strength and ductility are to be determined before actual use. For that the above test is conducted. A material when subjected to a tensile load resists the applied load by developing internal resisting force. This resistance comes due to atomic bonding between the atoms of the material. The resisting force per unit cross-sectional area is known as stress. The value of stress in material goes on increasing with the increase in applied tensile load, but it has a certain maximum limit too. The maximum stress, at which a material fails, is called Ultimate Tensile Strength. (UTS). All known materials are elastic in nature and so is the steel specimen also. Its initial length increase with increase in applied load followed with corresponding decrease in its lateral dimensions. Increase in length is called elongation which is a measure of ductility. The change in length over the original length is called strain. The ratio of stress to strain within the elastic limit is termed as modulus of elasticity. The end of elastic limit is indicated by the yield point. With increase in loading beyond the elastic limit, original area of cross-section goes on decreasing and finally reduces to is minimum value when the specimen breaks.4. Formula used:

Ultimate tensile strength ult =

Percentage elongation =

Yield strength = N/mm2

Percentage reduction in Area= Stress () = Strain () = l- is change in lengthLo- Original lengthUniversity of Petroleum & energy studies Dehradun 075. Experimental Procedure: The experiment is perormed in the following sequential manner1. First of all the gauge length is marked on the specimen. Its diameter and gauge length is also measured. The length may either be gauge length or the total length of the specimen.2. The load range of machines operation is selected, say 40 tones. It should be sufficiently higher then the expected value.3. Bring the dummy pointer on the load indicator close to the live pointer.4. Now the specimen is gripped between the upper and middle cross-head jaws of the machine.5. The machine is switched on by pressing the appropriate button on the control panel and the load is applied gradually by turning the control valve slowly.6. The elongation of the specimen is recorded for a certain specified load. The elongation can be measured with the help of vernier calipers. More frequent readings are taken as the yield point is approached.7. Continue the test till fracture occurs.8. Note down the maximum load at fracture indicated by the dummy pointer on the load indicator.9. Joined the cooled broken parts manually, and measure the extended gauge length and reduced diameter of the specimen.6. Observation:Following data are recorded during the tensile test.Original dimensions (Before fracture)Gauge length (Lo) = --------- mmDiameter (Do) = ------------ mmCross sectional area (Ao) = ---------- mm2 Final dimensions (After fracture)Length (Lf) = ------------ mmDiameter (Df) = -----------mmCross-sectional area (Af) = ---- mm S NoApplied load (P) KNElongation l(mm)Stress (N/mm2) P/AoStrain l/LoYield Load

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University of Petroleum & energy studies Dehradun 087. Calculations:Ultimate load (P) = ---------- KN = ---------- NYield load (Yo) =--------- KN =-----------N

Ultimate tensile strength ult =

Percentage elongation =

Yield strength = N/mm2

Percentage reduction in Area=8. Result: Ultimate tensile strength =----------N/mm2 Percentage elongation = -----------% Yield strength = ------------- Percentage reduction in Area= ---------

Specimen description

l= 5.65 for circular cross-section

l= 4 for rectangular cross-section, Where A is the cross-section area of the specimen.

University of Petroleum & energy studies Dehradun 099. Precautions and sources of error Ensure that the specimen is tightly gripped in the jaws Open the control valve slowly. Loosen the locking nuts slightly as soon as load pointer starts moving. Close the control valve immediately after fracture of specimen. Open the release valve slowly after operation Do not touch the specimen immediately after fracture.

10.0 Related short questions: What is strength? What is gauge length? What is poison Ratio? What is Hooks law? Which material are more elastic steel and rubber? What is stress? Tell the different types of stress? Draw the stress and strain graph of hard and ductile material. Which material has high tensile strength hard or ductile? What is bulk modulus?

University of Petroleum & energy studies Dehradun 10

Experiment No-05

OBJECT: To conduct Torsion test on Mild steel or cast iron specimen to find out modulus of rigidity

Experimental set up/Equipment/Apparatus/Tools Torsion testing machines A steel rule and caliper or micrometer Standard specimen of mild steelTheory and application: A Torsion test quite instrumental in determining the value of modulus of rigidity (ratio of shear stress to shear strain) of a metallic specimen. The value of modulus of rigidity can be found out through observations made during the experiment by using the torsion equationFormula used:

= therefore, C= Where T = Torque applied (N-m) Ip = Polar moment of inertia (m4) C = Modulus of rigidity = Angle of twist (radians) l = gauge length (meter)Experimental Procedure: Select the driving dogs to suit the size of the specimen and clamp it in the machine by adjusting the length of the specimen by means of a sliding spindle.Measure the diameter at about three places and take the average value.Choose the appropriate unit of torque on the microprocessor based load indicator.Reset the load indicator to zero.Set the protector to zero for convenience and clamp it by means of knurled screw.Carry out straining by rotating the hand wheel in appropriate direction.Load the machine in suitable increments, observing the recording.Then load out to failure as to cause equal increments of strain reading. Plot a torque- twist (T- ) graph.(T in N-m and in radian)Read off co- ordinates of a convenient point from the straight line portion of the torque- twist (T- ) graph and calculate the value of C by using the relation:

= Also calculate the value of C from the slope of the T- curve Observations:Gauge length of the specimen (l) = mDiameter of the specimen (d) = m

Polar moment of inertia Ip = 4 m4

Observation table: S NoAngle of twist (degree)Angle of twist (radians)Torque (KN-m/ Kg-m )Torque (N-M)

1----306090120150

Calculations:Slope of the straight portion of the torque-twist curve m =

Slope m =

Therefore C = Results:Modulus of rigidity C = N/mm2 Precautions and sources of error Change the angle of twist to radians before plotting the graph Do not untwist the specimen during operation. Keep distance from the chain- pulley mechanism.Related short Questions: What is torsion? What is modulus of rigidity? What is torsion rigidity? Which shaft is strong in torsion solid or hollow? Why railway track made of I- section?

University of Petroleum & energy studies Dehradun 13Experiment No-061. Object: To Conduct the Izod Impact test on Impact testing machine and find the impact strength and modulus of rupture of a given specimen.2. Experimental set up/Equipment/Apparatus/Tools i-Impact testing machineii-Izod test specimen of mild steel (75X10X10 mm) with 2mm notch

3. Theory and application: An Impact test signifies toughness of material that is ability of material to absorb energy during plastic deformation. Toughness takes into account both the strength and ductility of the material. Several engineering materials have to withstand impact or suddenly applied loads while in service. Impact strengths are generally lower as compared to strengths achieved under slowly applied loads. The test measures the notch toughness of material under shock loading. Values obtained from these tests are not of much utility to design problems directly and are highly arbitrary. Still it is important to note that it provides a good way of comparing toughness of various materials or toughness of same material under different conditions.4. Formula used: Notch impact strength I= N/m (1Jule=1 N-M)

Modulus of rupture = Jule/mm3Where Ae is effective area of specimen (in meter) Ve is effective volume of specimen (in mm)

5. Experimental Procedure: Following procedure should be adopted to conduct the test First measure the length, width and thickness of the specimen. Set the machine at 164Jules dial reading and lock the striking hammer in its top position at 800 with the vertical Now press down the pendulum release lever so that the hammer falls and sings past the bottommost position. Note down the reading on dial. This is initial reading(X). Remember that this reading is without any specimen and indicates frictional and windage (air) loss of energy of the hammer. 01 Now put the test- specimen on the support as a cantilever with the help of specimen setting fixture in proper manner such that notch is on the tension side. Release the lever so that the hammer strikes the test-piece and break it. Note down this reading. This is final reading(Y)

University of Petroleum & energy studies Dehradun 14 Make use of brake handle to stop the motion of hammer after its swing. Repeat the experiment on the other specimen(reading of three specimen is desired)6. Observation Table:Specimen NoSize of specimen(lXbXh) mmDepth of notch (mm)Initial reading(X) JulesFinal Reading(Y)Jules

7. Calculations: Impact Energy U = Y-X Jules

Notch impact strength I = N/m (1Jule=1 N-M)

Modulus of rupture = Jule/mm3Where Ae is effective area of specimen (in meter) Ve is effective volume of specimen (in mm)8. Results:9. Precautions and sources of error Measure the dimensions of the specimen carefully Place the specimen carefully so that the hammer strikes at the centre of the specimen Note down reading carefully Operate the machine from outside the boundary10. Related short Questions: What is toughness? What is proof resilience? What is resilience? Which material is tough hard or ductile? If temperature increases the toughness increase or decrease? Why notch provide in specimen? If notch not provide in specimen then which type of fracture accurse? Give any examples where tough is importance?

University of Petroleum & energy studies Dehradun 15Experiment No-07

1. Object: To conduct the charpy Impact test on Impact testing machine and find the Impact strength of a given specimen. 2. Experimental set up/Equipment/Apparatus/Tools i- Impact testing machineii- Charpy test specimen of mild steel( 55X10X10 mm) with 2mm notch3. Theory and application: An Impact test signifies toughness of material that is ability of material to absorb energy during plastic deformation. Toughness takes into account both the strength and ductility of the material. Several engineering materials have to withstand impact or suddenly applied loads while in service. Impact strengths are generally lower as compared to strengths achieved under slowly applied loads. The test measures the notch toughness of material under shock loading. Values obtained from these tests are not of much utility to design problems directly and are highly arbitrary. Still it is important to note that it provides a good way of comparing toughness of various materials or toughness of same material under different conditions.

4. Formula used: Notch impact strength I= N/m (1Jule=1 N-M)

Modulus of rupture = Jule/mm3Where Ae is effective area of specimen (in meter) Ve is effective volume of specimen (in mm)5. Experimental Procedure: Following procedure should be adopted to conduct the test First measure the length, width and thickness of the specimen. Set the machine at 300 Jules dial reading and lock the striking hammer in its top position 1600 Now press down the pendulum release lever so that the hammer falls and sings past the bottommost position. Note down the reading on dial. This is initial reading(X). Remember that this reading is without any specimen and indicates frictional and windage (air) loss of energy of the hammer. Now put the test- specimen on the support provided as simply supported beam with the face with notch on the tension side. Release the lever so that the hammer strikes the test-piece and break it. Note down this reading. This is final reading(Y) Repeat the experiment on the other specimen(reading of three specimen is desired)

University of Petroleum & energy studies Dehradun 16Observation Table:Specimen NoSize of specimen(lXbXh) mmDepth of notch (mm)Initial reading(X) JulesFinal Reading(Y) Jules

7. Calculations: Impact Energy U= Y-X Jules

Notch impact strength I= N/m (1Jule=1 N-M)

Modulus of rupture = Jule/mm3Where Ae is effective area of specimen (in meter) Ve is effective volume of specimen (in mm)8. Results: Impact energy of given specimen is =Notch Impact strength of given specimen is =Modulus of rupture of given specimen is =

9. Precautions and sources of error Measure the dimensions of the specimen carefully Place the specimen carefully so that the hammer strikes at the centre of the specimen Note down reading carefully Operate the machine from outside the boundary10.0 Related short questions: What is toughness? What is proof resilience? What is resilience? Which material is tough hard or ductile? If temperature increases the toughness increase or decrease? Why notch provide in specimen? If notch not provide in specimen then which type of fracture accurse? Give any examples where tough is importance?

University of Petroleum & energy studies Dehradun 17

Specifications: Specifications:Pendulum drop angle1400Pendulum effective weight20.59 kgPendulum speed5.3465 m/secDistance of Axes of hammer rotation and center of test piece825mmImpact energy300 Jules

University of Petroleum & energy studies Dehradun 18Experiment No. 8Object:To perform the shear test on UTM.Apparatus used: A UTM, Specimen, shearing attachment, vernier caliper or outside caliper etc.Theory and application: - A type of force which causes or tends to cause two contiguous parts of the body to slide relative to each other in a direction parallel to their plane of contact is called the shear force. The stress required to produce fracture in the plane of cross-section, acted on by the shear force is called shear strength.Formula used: Ultimate shear strength = N/mm2s = N/mm2Experimental procedure:- First measure diameter of specimen (pin) by using our side caliper or vernier caliper Take the suitable test rig (shear die) and insert the pin in given hole in test rig Put the test rig on the bottom carriage. Select the suitable range of loads on machine. Adjust the middle carriage over the test rig through electrically system. Bring the dummy pointer on the load indicator close to the live pointer. The machine is switched on by pressing the appropriate button on the control panel and the load is applied gradually by turning the control valve slowly. Continue the test till fracture occurs. Note down the maximum load at fracture indicated by the dummy pointer on the load indicator.

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Observation:- Applied compressive force (W) = ------- Newton Diameter of specimen d = ------ mm.Calculation: - Cross sectional area of the pin (in double shear) = 2xd2 mm2Load taken by the specimen at the time of failure, W = ---- (Newton)The shear strength shall be calculated from the following formulae: s = N/mm2Whered is the actual diameter of the specimen Precautions and sources of error:- The specimen should be all place equal dia. Measure the diameter of specimen carefully. Take reading more carefully. After shearing specimen stop to m/c.Related short questions:- Does the shear failure in wood occur along the 45 shear plane? What is budging? Why does it occur? What is single & double shear? What is finding in shear test? What is unit of shear strength?

University of Petroleum & energy studies Dehradun 20

Experiment No. 9

1.0 Object: To conduct the compression test on a UTM and determine the ultimate compressive strength for a given specimen (C.I, Brick, wooden)Equipment:2.0 Experimental set up/Equipment/Apparatus/Tools Universal testing Machine Vernier caliper/out side caliper Test specimen( Brick, wooden or C.I)3.0 Theory and application: Various machine and structural components are subjected to compressive load in numerous operations. For safe design of these components their ultimate compressive strength are to be determined before actual use. For that the above test is conducted.Failure mode: The procedure of experimentation and observation of data are almost similar to that of the tension test. Most compressive test are performed on brittle materials. Generally they failed in shear. Shear develops along a diagonal plane. The maximum shear stress develops on a plane inclined at 450 from the direction of compressive load. However the spread of shear cracks may be deviated from this plane due the effects of end restraint. It can be noticed cast iron and concrete. The directionality of grains in wood also effects the shear failure along the 450 shear plan.4.0 Formula used: Ultimate compressive strength = N/mm2Stress () = Strain () = l- is change in lengthL- Original length

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5.0 Experimental Procedure: The experiment is performed in the following sequential-1. First measure the dimensions of specimen and calculate the cross-sectional area.2. The load range of machines operation is selected as required3. Bring the dummy pointer on the load indicator close to the live pointer. 4. Now the specimen put on the bottom carriage.5. The machine is switched on by pressing the appropriate button on the control panel and the load applied is gradually by turning the control valve slowly.6. Elongation of the specimen is recorded for a certain specified load.7. Continue the test till fracture occurs8. Note down the maximum load at fracture indicated by the dummy pointer on the load indicator.6.0 Observations:Diameter of specimen (D) = ---------- mmCross-sectional area (A) = ---------- mm2 OrDimensions of specimen

Length (l)= ------- mm Width (b) = ------- mm Cross-section area (Ao) lXb =---------- mm2

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S.No.Applied load(P) NElongation(l) mmStress()P/Ao (N/mm2)Strain()(l)/L

7.0 Calculation:Ultimate load (P) = KN = NUltimate compressive strength = N/mm2 Stress () = Strain () = l- is change in lengthL- Original length 8.0 Results: Ultimate compressive strength of given specimen= ------9.0 Precautions and sources of error: Open the control valve slowly. Loosen the locking nuts slightly as soon as load pointer starts moving. Close the control valve immediately after fracture of specimen. Open the release valve slowly after operation Do not touch the specimen immediately after fracture.

10.0 Related short question: Compression tests are generally performed on brittles materials-why? How do ductile and brittle materials in their behavior in compression test? What is column action? How does the h/d ratio of specimen affect the test result?

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