Mechanics of Materials Lab report.

User Generated

unzzrq

Writing

Description

I have everything you need to write this Lab report including:

Lab report Template.

Data and figures.

reference sheet.

Rubric to follow to write this report. ( Follow the lab report template, it has everything you need to follow to write it and the way you list the figures)

Unformatted Attachment Preview

American Association State Highway and Transportation Officials Standards AASHTO No: T67 Designation: E 4 – 07 Standard Practices for Force Verification of Testing Machines1 This standard is issued under the fixed designation E 4; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval. This standard has been approved for use by agencies of the Department of Defense. 2. Referenced Documents 2.1 ASTM Standards: 2 D 76 Specification for Tensile Testing Machines for Textiles E 74 Practice of Calibration of Force-Measuring Instruments for Verifying the Force Indication of Testing Machines E 467 Practice for Verification of Constant Amplitude Dynamic Forces in an Axial Fatigue Testing System 1. Scope 1.1 These practices cover procedures for the force verification, by means of standard calibration devices, of tension or compression, or both, static or quasi-static testing machines (which may, or may not, have force-indicating systems). These practices are not intended to be complete purchase specifications for testing machines. Testing machines may be verified by one of the three following methods or combination thereof: 1.1.1 Use of standard weights, 1.1.2 Use of equal-arm balances and standard weights, or 1.1.3 Use of elastic calibration devices. 3. Terminology 3.1 Definitions: 3.1.1 testing machine (force-measuring type)—a mechanical device for applying a force to a specimen. 3.1.1.1 portable testing machine (force-measuring type)—a device specifically designed to be moved from place to place and for applying a force (load) to a specimen. 3.1.2 tension testing machine, CRT (constant-rateoftraverse)—a mechanical device for applying a load (force) to a specimen and in which the force is measured by means of a pendulum. 3.1.3 force—in the case of testing machines, a force measured in units such as pound-force, newton, or kilogram-force. 3.1.3.1 Discussion—The pound-force is that force which acting on a 1-lb mass will give to it an acceleration of 9.80665 m/s2(32.1740 ft/s2). The newton is that force which acting on a 1-kg mass will give to it an acceleration of 1 m/s2. 3.1.4 accuracy—the specified permissible variation from the correct value. A testing machine is said to be accurate if the indicated force is within the specified permissible variation from the actual force. 3.1.4.1 Discussion—In these methods the word “accurate” applied to a testing machine is used without numerical values, for example, “An accurate testing machine was used for the investigation.” The accuracy of a testing machine should not be confused with sensitivity. For example, a testing machine might be very sensitive; that is, it might indicate quickly and NOTE 1—These practices do not cover the verification of all types of testing machines designed to measure forces, for example, the constantrate-of-loading type which operates on the inclined-plane principle. This type of machine may be verified as directed in the applicable appendix of Specification D 76. 1.2 The procedures of 1.1.1-1.1.3 apply to the verification of the force-indicating systems associated with the testing machine, such as a scale, dial, marked or unmarked recorder chart, digital display, etc. In all cases the buyer/owner/user must designate the force-indicating system(s) to be verified and included in the report. 1.3 Since conversion factors are not required in this practice, either inch-pound units, SI units, or metric values can be used as the standard. 1.4 Forces indicated on displays/printouts of testing machine data systems—be they instantaneous, delayed, stored, or retransmitted—which are verified with provisions of 1.1.1, 1.1.2, or 1.1.3, and are within the 61 % accuracy requirement, comply with Practices E 4. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 1 These practices are under the jurisdiction of ASTM Committee E28 on Mechanical Testing and is the direct responsibility of Subcommittee E28.01 on Calibration of Mechanical Testing Machines and Apparatus. Current edition approved Jan. 1, 2007. Published January 2007. Originally approved in 1923. Last previous edition approved in 2003 as E 4 – 03. 2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards volume information, refer to the standard’s Document Summary page on the ASTM website. Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States. 1 E 4 – 07 3.1.12 resolution of the force indicator—smallest change of force that can be estimated or ascertained on the force indicating apparatus of the testing machine, at any applied force. Appendix X1. describes a method for determining resolution. 3.1.12.1 resolution of analog type force indicators (scales, dials, recorders, etc.)—the resolution is the smallest change in force indicated by a displacement of a pointer, or pen line. The resolution is calculated by multiplying the force corresponding to one graduation by the ratio of the width of the pointer or pen line to the center to center distance between two adjacent graduation marks. The typical ratios used are 1:1, 1:2, 1:5, or 1:10. A spacing of 0.10 in. (2.5 mm) or greater is recommended for the ratio of 1:10. A ratio less than 1:10 should not be used. (1) Discussion—If a force indicating dial has graduations spaced every 0.080 in. (2.0 mm), the width of the pointer is approximately 0.040 in. (1.0 mm), and one graduation represent 5 lbf (25N). The ratio used would be 1:2 and the resolution would be equal to 2-1/2 lbf (12-1/2 N). 3.1.12.2 resolution of digital type force indicators (numeric, displays, printouts, etc.)—the resolution is the smallest change in force that can be displayed on the force indicator, at any applied force. (1) Discussion—A single digit or a combination of digits may be the smallest change in force that can be indicated. 3.1.13 If the force indication, for either type of force indicator, fluctuates by more than twice the resolution, as described in 3.1.12.1 or 3.1.12.2, the resolution, expressed as a force, shall be equal to one-half the range of the fluctuation. definitely small changes in force, but nevertheless, be very inaccurate. On the other hand, the accuracy of the results is in general limited by the sensitivity. 3.1.5 error (or the deviation from the correct value)—in the case of a testing machine, the difference obtained by subtracting the force indicated by the calibration device from the force indicated by the testing machine. 3.1.5.1 Discussion—The word “error” shall be used with numerical values, for example, “At a force of 30 000 lbf (133 kN), the error of the testing machine was + 15 lbf (67 N).” 3.1.6 percent error—in the case of a testing machine, the ratio, expressed as a percent, of the error to the correct value of the applied force. 3.1.6.1 Discussion—The test force, as indicated by the testing machine, and the applied force, as computed from the readings of the verification device, shall be recorded at each test point. The error, E, and the percent error, Ep, shall be calculated from these data as follows: E5A2B (1) Ep 5 [~A 2 B!/B] 3 100 where: A = force indicated by machine being verified, lbf (or N), and B = correct value of the applied force, lbf (or N), as determined by the calibration device. 3.1.7 correction—in the case of a testing machine, the difference obtained by subtracting the indicated force from the correct value of the applied force. 3.1.8 permissible variation (or tolerance)—in the case of testing machines, the maximum allowable error in the value of the quantity indicated. 3.1.8.1 Discussion—It is convenient to express permissible variation in terms of percentage of error. The numerical value of the permissible variation for a testing machine is so stated hereafter in these practices. 3.1.9 capacity range—in the case of testing machines, the range of forces for which it is designed. Some testing machines have more than one capacity range, that is, multiple ranges. 3.1.10 verified range of forces—in the case of testing machines, the range of indicated forces for which the testing machine gives results within the permissible variations specified. 3.1.10.1 calibration, n—in the case of force testing machines, the process of comparing the force indication of the machine under test to that of a standard, making adjustments as needed to meet error requirements. 3.1.10.2 verification, n—in the case of force testing machines, the process of comparing the force indication of the machine under test to that of a standard and reporting results, without making adjustments. 3.1.11 elastic calibration device—a device for use in verifying the force readings of a testing machine consisting of an elastic member(s) to which forces may be applied, combined with a mechanism or device for indicating the magnitude (or a quantity proportional to the magnitude) of deformation under force. 4. Significance and Use 4.1 Testing machines that apply and indicate force are used in many industries, in many ways. They may be used in a research laboratory to measure material properties, and in a production line to qualify a product for shipment. No matter what the end use of the machine may be, it is necessary for users to know the amount of force that is applied and indicated, and that the accuracy of the force is traceable to the National Institute of Standards and Technology (NIST), formerly NBS. Practices E 4 provides a procedure to verify these machines, in order that the indicated forces may be traceable. A key element to this NIST traceability is that the devices used in the verification have known force characteristics, and have been calibrated in accordance with Practice E 74. 4.2 The procedures in Practices E 4 may be used by those using, manufacturing, and providing calibration service for testing machines and related instrumentation. 5. Calibration Devices 5.1 When verifying testing machines, use calibration devices only over their Class A force ranges as determined by Practice E 74. 6. Advantages and Limitations of Methods 6.1 Verification by Standard Weights—Verification by the direct application of standard weights to the weighing mechanism of the testing machine, where practicable, is the most accurate method. Its limitations are: (1) the small range of 2 E 4 – 07 7.3.1 Introduction of the new force measuring devices shall require that interchangeability be established per 7.3. 7.4 A Practices E 4 Verification consists of at least two verification runs of the forces contained in the force range(s) selected. See 10.1 and 10.3. 7.4.1 If the initial verification run produces values within the Practices E 4 requirements of Section 18, the data may be used “as found” for run one of the two required for the new verification report. 7.4.2 If the initial verification run produces any values which are outside of the Practices E 4 requirements, the “as found” data may be reported and may be used in accordance with applicable quality control programs. Calibration adjustments shall be made to the force indicator system(s), after which the two required verification runs shall be conducted and reported in the new verification report and certificate. 7.4.3 Calibration adjustments may be made to improve the accuracy of the system. They shall be followed by the two required verification runs, and issuance of a new verification report and certificate. forces that can be verified, (2) the nonportability of any large amount of standards weights, and (3) its nonapplicability to horizontal testing machines or vertical testing machines having weighing mechanisms that are not designed to be actuated by a downward force. 6.2 Verification by Equal-Arm Balance and Standard Weights—The second method of verification of testing machines involves measurement of the force by means of an equal-arm balance and standard weights. This method is limited to a still smaller range of forces than the foregoing method, and is generally applicable only to certain types of hardness testing machines in which the force is applied through an internal lever system. 6.3 Verification by Elastic Calibration Devices—The third method of verification of testing machines involves measurement of the elastic strain or deflection under force of a ring, loop, tension or compression bar, or other elastic device. The elastic calibration device is free from the limitations referred to in 6.1 and 6.2. 7. System Verification 7.1 A testing machine shall be verified as a system with the force sensing and indicating devices (see 1.2 and 1.4) in place and operating as in actual use. 7.1.1 If this is not technically possible, refer to Annex A1, Verifying the Force Measuring System out of the Test Machine. Out of the test machine verifications shall be in accordance with the main body of Practices E 4 and its Annex A1 7.2 System verification is invalid if the devices are removed and checked independently of the testing machine unless verification is performed according to Annex A1. 7.3 Many testing machines utilize more than one force measuring device in order to obtain more accurate force indication at lower applied forces. These devices are routinely installed and uninstalled in the testing machine. For such devices, interchangeability shall be established during the initial verification and shall be reestablished after an adjustment is performed. This is accomplished by performing a normal verification with the device in place as during normal use. It is advisable that orientation be kept consistent, such as by noting the direction of the cable connector so that when reinstalling the device, the orientation will be repeated. Remove and reinstall the device between the two verification runs to demonstrate interchangeability. Repeat the procedure for each interchangeable force measuring device used in the testing machine. 8. Gravity and Air Buoyancy Corrections 8.1 In the verification of testing machines, where standard weights are used for applying forces directly or through lever or balance-arm systems, correct the force for the local value of gravity and for air buoyancy. 8.2 Calculate the force exerted by a weight in air as follows: S Mg d Force 5 9.80665 1 2 D D (2) where: M = mass of the weight, g = local acceleration due to gravity, m/s2, d = air density (0.0012 Mg/m3), and D = density of the weight in the same units as d. For use in verifying testing machines, corrections for local values of gravity and air buoyancy can be made with sufficient accuracy using the multiplying factors from Table 1. NOTE 2—If M, the mass of the weight is in pounds, the force will be in pounds-force units. If M is in kilograms, the force will be in kilogramforce units. These customary force units are related to the newton, the SI unit of force, by the following relationships: 1 lbf 5 4.448222 N1 kgf 5 9.80665 N ~exact! (3) 9. Application of Force 9.1 In the verification of a testing machine, approach the force by increasing the force from a lower force. TABLE 1 Unit Force Exerted by a Unit Mass in Air at Various Latitudes Elevation Above Sea Level, ft(m) Latitude,° −100 to 500 (−30.5 to 152) 500 to 1500 (152 to 457) 1500 to 2500 (457 to 762) 2500 to 3500 (762 to 1067) 3500 to 4500 (1067 to 1372) 4500 to 5500 (1372 to 1676) 20 25 30 35 40 45 50 55 0.9978 0.9981 0.9985 0.9989 0.9993 0.9998 1.0003 1.0007 0.9977 0.9980 0.9984 0.9988 0.9993 0.9997 1.0002 1.0006 0.9976 0.9979 0.9983 0.9987 0.9992 0.9996 1.0001 1.0005 0.9975 0.9979 0.9982 0.9987 0.9991 0.9996 1.0000 1.0005 0.9975 0.9978 0.9982 0.9986 0.9990 0.9995 0.9999 1.0004 0.9974 0.9977 0.9981 0.9985 0.9989 0.9994 0.9999 1.0003 3 E 4 – 07 NOTE 3—For any testing machine the errors observed at corresponding forces taken first by increasing the force to any given test force and then by decreasing the force to that test force, may not agree. Testing machines are usually used under increasing forces, but if a testing machine is to be used under decreasing forces, it should be calibrated under decreasing forces as well as under increasing forces. NOTE 6—Example: A testing machine has a full-scale range of 5000 lbf and the resolution of the force indicator is 0.0472 lbf. The lowest possible verified force is 9.44 lbf (0.0472 3 200). Instead of decades starting at 9.44, 94.4 and 944 lbf, three decades, starting at 10, 100, and 1000 lbf are selected to cover the verified range of forces. Suitable verification forces are 10, 20, 40, 70, 100, 200, 400, 700, 1000, 2000, 3000, 4000, 5,000 lbf. Note that the uppermost decade is not a complete decade and is terminated with the upper limit of the verified force range. The 3000 lbf reading was added because the difference between 2000 and 4000 was greater than one-third of 5000. If the alternative distribution of forces is used, the verification forces selected would be 10, 25, 50, 75, 100, 250, 500, 750, 1000, 2500, 3750, 5000. 9.2 Testing machines that contain a single test area and possess a bidirectional loading and weighing system must be verified separately in both modes of weighing. 9.3 High-speed machines used for static testing must be verified in accordance with Practices E 4. 10.4 All selected verification forces shall be applied twice during the verification procedure. Applied forces on the second run are to be approximately the same as those on the first run. 10.5 Approximately 30 s after removing the maximum force in a range, record the return to zero indicator reading. This reading shall be 0.0 6 either the resolution, 0.1 % of the maximum force just applied, or 1 % of the lowest verified force in the range, whichever is greater. NOTE 4—Caution: Practices E 4 verification values are not to be assumed valid for high-speed or dynamic testing applications (see Practice E 467). NOTE 5—The error of a testing machine of the hydraulic-ram type, in which the ram hydraulic pressure is measured, may vary significantly with ram position. To the extent possible such machines should be verified at the ram positions used. 10. Selection of Verification Forces 10.1 Determine the upper and lower limits of the verified force range of the testing machine to be verified. In no case shall the verified force range include forces below 200 times the resolution of the force indicator. 10.2 If the lower limit of the verified force range is greater than or equal to one-tenth of the upper limit, five or more different verification forces shall be selected such that the difference between two adjacent verification forces is greater than or equal to one twentieth and less than or equal to one-third the difference between the upper and lower limits of the verified force range. One verified force shall be the lower limit of the verified force range and another verified force shall be the upper limit. (Fewer verification forces are required for testing machines designed to measure only a small number of discrete forces, such as certain hardness testers, creep testers, etc.) 10.3 If the lower limit of the verified force range is less than one-tenth the upper limit, verification forces shall be selected as follows: 10.3.1 Starting with the lower limit of the verified force range, establish overlapping force decades such that the maximum force in each decade is ten times the lowest force in the decade. The lowest force in the next higher decade is the same as the highest force in the previous decade. The highest decade might not be a complete decade. 10.3.2 Five or more different verification forces shall be selected per decade such that the difference between two adjacent verification forces is greater than or equal to onetwentieth and less than or equal to one-third the difference between the maximum and the minimum force in that decade. It is recommended that starting with the lowest force in each decade, the ratio of the verification forces to the lowest force in the decade are 1:1, 2:1, 4:1, 7:1, 10:1 or 1:1, 2.5:1, 5:1, 7.5:1, 10:1. 10.3.3 If the highest decade is not a complete decade, choose verification forces at the possible ratios and include the upper limit of the verified force range, If the difference between two adjacent verification forces is greater than onethird of the upper limit, add an additional verification force. 11. Eccentricity of Force 11.1 For the purpose of determining the verified force range of a testing machine, apply all calibration forces so that the resultant force is as nearly along the axis of a testing machine as is possible. NOTE 7—The effect of eccentric force on the accuracy of a testing machine may be determined by verification readings taken with calibration devices placed so that the resultant force is applied at definite distances from the axis of the machine, and the verified force range determined for a series of eccentricities. A. VERIFICATION BY STANDARD WEIGHTS 12. Procedure 12.1 Place standard metal weights of suitable design, finish, and adjustment on the weighing platform of the testing machine or on trays or other supports suspended from the force measuring mechanism in place of the specimen. Use weights certified within five years to be correct within a limit of error of 0.1 %. Apply the weights in increments and remove in the reverse order. Arrange the weights symmetrically with respect to the weighing platform, so that the center of gravity of the force lies in the vertical line through the center of the platform. Record the applied force and the indicated force for each test load applied, and the error and the percent error calculated from these data. NOTE 8—The method of verification by direct application of standard weights can be used only on vertical testing machines in which the force on the weighing table, hydraulic support, or other weighing device is downward. The total force is limited by the size of the platform and the number of weights available. Fifty-pound (22.7-kg) weights are usually convenient to use. This method of verification is confined to small testing machines and is rarely used above 1000 or 2000 lb. NOTE 9—In connection with the required limit of error of 0.1 % it may be noted that, in addition to the National Institute for Standards and Technology, many of the states, some counties, and some universities have departments or offices of weights and measures equipped and staffed to certify weights to tolerances closer than the requirement of a limit of error of 0.1 %. 4 E 4 – 07 only within its Class A force range and identified with the verification readings for which it is used. 15.2 To ensure a stable zero, flex the elastic device from no force to the maximum force at which the device will be used. Repeat as necessary, allowing sufficient time for stability. 15.3 There are two methods for using elastic calibration devices: 15.3.1 Follow-the-Force Method—The force on the elastic calibration device is followed until the force reaches a nominal graduation on the force-readout scale of the testing machine. Record the force on the elastic calibration device. 15.3.2 Set-the-Force Method—The nominal force is preset on the elastic calibration device, and the testing machine force readout is read when the nominal force on the elastic calibration device is achieved. 15.4 After selecting suitable test force increments, obtain zero readings for both machine and elastic device, and apply forces slowly and smoothly during all verification measurements. 15.5 The calibration procedure must ensure that use of the maximum force indicator, recorder, or other accessory force devices does not cause testing machine errors to exceed the acceptable tolerances of 18.1. 15.6 Record the indicated force of the testing machine and the applied force from the elastic calibration device (temperature corrected as necessary), as well as the error and percentage of error calculated from the readings. 15.7 Under certain conditions, multi-device setups may be used in compression loading. All devices to be loaded in parallel should be the same height (shims may be used) and the machine’s load axis should be coincidental with the force axis of the device setup. This is necessary so that a net moment is not applied to the testing machine loading member. Multidevice setups are not recommended unless the use of a single calibration device is not practical. B. VERIFICATION OF HARDNESS TESTING MACHINES BY EQUAL-ARM BALANCE AND STANDARD WEIGHTS 13. Procedure 13.1 Position the balance so that the indenter of the testing machine being calibrated bears against a block centered on one pan of the equal-arm balance, the balance being in its equilibrium position when the indenter is in that portion of its travel normally occupied when making an impression. Place standard weights complying with the requirements of Section 12 on the opposite pan to balance the load exerted by the indenter. NOTE 10—This method may be used for the verification of testing machines other than hardness-testing machines by positioning the forceapplying member of the testing machine in the same way that the indenter of a hardness-testing machine is positioned. For other methods of verifying hardness testing machines see the applicable ASTM test method. 13.2 Since the permissible travel of the indenter of a hardness-testing machine is usually very small, do not allow the balance to oscillate or swing. Instead, maintain the balance in its equilibrium position through the use of an indicator such as an electric contact, which shall be arranged to indicate when the reaction of the indenter force is sufficient to lift the pan containing the standard weights. 13.3 Using combinations of fractional weights, determine both the maximum value of the dead-weight force that can be lifted by the testing machine indenter force during each of ten successive trials, and the minimum value that cannot be lifted during any one of ten successive trials. Take the correct value of the indenting force as the average of these two values. The difference between the two values shall not exceed 0.5 % of the average value. C. VERIFICATION BY ELASTICCALIBRATION DEVICE 14. Temperature Equalization 14.1 When using an elastic calibration device to verify the readings of a testing machine, place the device near to, or preferably in, the testing machine a sufficient length of time before the test to assure that the response of device is stable. 14.2 During the verification, measure the temperature of the elastic device within 62°F or 61°C by placing a calibrated thermometer as close to the device as possible. 14.3 Elastic calibration devices not having an inherent temperature-compensating feature must be corrected mathematically for the difference between ambient temperature and the temperature to which its calibration is referenced. Temperature-correction coefficients should be furnished (if applicable) by the manufacturer of the calibration device. Refer to Practice E 74 for further information. 16. Constant-Rate-of-Traverse CRT-Type Testing Machines 16.1 In the verification of pendulum-type testing machines having capacities of 2000 lbf or 10 kN or less, special procedures must be followed in order to properly account for the effects of friction, inertia, etc. These machines are usually of the vertical type and usually can be verified by standard weights. For pendulum-type tension-testing machines in which the forces act in a horizontal direction or when verification by standard weights is not practical, other methods of verification may be used. In such cases, devices similar to the equal-arm balances, or the elastic calibrating devices may be used, provided precautions as set forth herein are taken. 16.2 Either or both of two alternative procedures (see 16.5 and 16.6) may be used, depending on the requirements of specifications of materials to be tested, recommendations of the testing machine manufacturer, or other pertinent consideration. 16.3 For any range of forces, verify the tension-testing machine with at least five test forces. Each successive test load shall differ from the previous test force by not more than one third of the difference between the maximum and minimum test forces. 15. Procedure 15.1 Place the elastic device in the testing machine so that its center line coincides with the center line of the heads of the testing machine. Record the Practice E 74 Class A verification value which establishes the lowest limit, or force level, allowable for the calibration device’s loading range (see Practice E 74). Each elastic calibration device is to be used 5 E 4 – 07 CALCULATION AND REPORT 16.3.1 For CRT machines, the verified range of force shall in no case include forces below 15 % of the capacity range. 16.4 Except as set forth in Section 16, other requirements of Practices E 4 shall be applicable. 16.5 Procedure 1 (Pawls Inoperative): 16.5.1 Verify the machine in the condition under which it is to be used, with all attachments and recording mechanisms in operation as they are to be used in actual testing, except that any pawls or other detents in the weighing mechanism shall have been rendered inoperative. In verification, apply the test force and minimize the effect of friction by gently oscillating the pendulum to ensure that the force of the applied test force is in equilibrium with the force exerted by the pendulum. 16.5.2 Examine the machine to detect any friction or slack in the weighing, indicating, or recording mechanisms and estimate the actual effect in terms of units in which the machine is calibrated. 16.5.3 Follow 16.6 to determine the effects described in 16.5.2. 16.6 Procedure 2 (Pawls Operating): 16.6.1 Verify the machine in the condition under which it is to be used with all attachments and recording mechanisms in operation as they are to be used in actual testing. In verification, apply the test force with the pawls or other detents in the normal operating position. After the pendulum has come to rest, disengage the pawls or detents, if any, and depress the pendulum slightly as if the force were decreased (approximately 5 % of the capacity range). Next, with the pawls or detents engaged, release the pendulum smoothly and at a rate approximately the rate of movement of the pendulum during an actual test. The point at which the system comes to rest under these conditions shall be taken as the indicated force on the machine. 18. Basis of Verification 18.1 The percent error for forces within the range of forces of the testing machine shall not exceed 61.0 %. The algebraic difference between errors of two applications of same force (repeatability) shall not exceed 1.0 % (see 10.1 and 10.3). NOTE 11—This means that the report of the verification of a testing machine will state within what verified range of forces it may be used, rather than reporting a blanket acceptance or rejection of the machine. In machines that possess multiple-capacity ranges, the verified range of forces of each must be stated. 18.2 In no case shall the verified range of forces be stated as including forces outside the range of forces applied during the verification test. 18.3 Testing machines may be more or less accurate than the allowable 61.0 % error, or more or less repeatable than 1.0 %, which are the Practices E 4 verification basis. Buyers/ owners/users or product specification groups might require or allow larger or smaller error systems. Systems with accuracy errors larger than 61.0 % or repeatability errors larger than 1.0 % do not comply with Practices E 4. 19. Corrections 19.1 The indicated force of a testing machine that exceeds the permissible variation shall not be corrected either by calculation or by the use of a calibration diagram in order to obtain values within the required permissible variation. 20. Time Interval Between Verifications 20.1 It is recommended that testing machines be verified annually or more frequently if required. In no case shall the time interval between verifications exceed 18 months (except for machines in which a long-time test runs beyond the 18-month period). In such cases, the machine shall be verified after completion of the test. 20.2 Testing machines shall be verified immediately after repairs (this includes new or replacement parts, or mechanical or electrical adjustments) that may in any way affect the operation of the weighing system or the values displayed. 20.2.1 Examples of new or replacement parts which may not effect the operation of the weighing system are: printers, computer monitors, keyboards, and modems. 20.3 Verification is required immediately after a testing machine is relocated (except for machines designed to be moved from place to place in normal use), and whenever there is a reason to doubt the accuracy of the force indicating system, regardless of the time interval since the last verification. 17. Lever-Type Creep-Rupture Testing Machines 17.1 Lever-type creep-rupture machines, which do not have a force-indicating device, may be verified using standard weights or elastic calibration device(s), or both. Weights used for verification should conform to the requirements of 12.1. In using an elastic calibration device, the requirements of Sections 14 and 15 must be met as applicable. 17.2 Procedure: 17.2.1 Place the calibration device in the testing machine and adjust the counterbalance (if the machine is so equipped) to compensate for the weight of the calibration device. 17.2.2 Connect the lower crosshead of the machine to the calibration device, and apply forces using standard weights in increments conforming to the provisions of 10.1. 17.2.3 Since many lever-type creep-rupture machines do not have a provision for adjustment of the lever ratio or tare, or both, it may be necessary to determine the “best fit” straight line through the calibration data, using the least squares method. By doing this, the actual lever ratio and tare of each machine can be determined, and thus reduce force errors due to small variations of lever ratios. Maximum errors should not exceed the requirements stated in 18.1. 21. Accuracy Assurance Between Verifications 21.1 Some product-testing procedures may require daily, weekly, or monthly spot checks to ascertain that a testing machine is capable of producing accurate force values between the testing machine verifications specified in Section 20. 21.2 Spot checks may be performed on ranges of interest or at force levels of interest utilizing a calibration device that complies with Methods A, B, and C as applicable. Elastic calibration devices must meet Class A requirements of Practice E 74 for the force level(s) at which the spot checks are made. 6 E 4 – 07 22.1.9 Statement identifying the force-indicating systems that were verified (for testing machines having more than one type of indicating system), 22.1.10 Indicated force of the testing machine and applied force indicated by the calibration device for each run at each verification force for each force-indicating system verified, 22.1.11 Testing machine error, percent error, and alegebraic error difference (repeatability) for each force-indicating system at each force point, 22.1.12 Verified range of forces of each force-indicating system of the testing machine and associated resolutions(s), 22.1.13 Return to zero reading for each range (see 10.5), 22.1.14 Statement that verification has been performed in accordance with Practice E 4 – XX. It is recommended that verification be performed in accordance with the latest published issue of Practice E 4, and 22.1.15 Names of calibration personnel and witnesses (if required). 21.3 Make spot checks at approximately 20 % and 80 % of a range unless otherwise agreed upon or stipulated by the material supplier/user. 21.4 Testing machine error shall not exceed 61.0 % of the spot check applied forces. Should errors be greater than 61.0 % at any of the spot check force levels, verify the testing machine immediately (see 20.3). 21.5 Maintain a record of the spot check tests which shall include the name, serial number, verification date, verification agency, and the minimum Class A, Practice E 74 value of the calibrating device(s) used to make spot checks; also include the name of person making the spot checks. 21.6 The testing machine shall be considered verified up to the date of the last successful spot check verification (see 21.4), provided that the testing machine is verified in accordance with Section 20 on a regular schedule. Otherwise spot checks are not permitted. 21.7 When spot checks are made, a clear, concise record must be maintained as agreed upon between the supplier and the user. The record must also contain documentation of the regular verification data and schedule. 23. Certificate 23.1 A certificate shall be prepared and signed by the person in responsible charge of the verification which shall include the following: 23.1.1 Name of calibrating agency, 23.1.2 Testing machine description and serial number, 23.1.3 Date of certification, 23.1.4 Identification of verified force-indicating systems, 23.1.5 Verified range(s) of force for each force-indicating system of the testing machine, 23.1.6 Maximum verified range tolerance in percent, and 23.1.7 Serial number, verified range of force, and calibration date of testing devices used for verification. 23.2 The certificate shall be error-free, and contain no alteration of data, dates, etc. 23.2.1 The certificate shall clearly reference associated report(s), when supplied. 22. Report 22.1 Prepare a clear and complete report of each verification of a testing machine which shall include the following: 22.1.1 Name of the calibrating agency, 22.1.2 Date of verification, 22.1.3 Testing machine description, serial number, and location, 22.1.4 Method of verification used, 22.1.5 Serial number and manufacturer of all devices used for verification, 22.1.6 Statement of how, by whom, and when the calibration of the apparatus used in verifying the testing machine was made, 22.1.7 Class A range of forces, in accordance with Practice E 74, for each calibration device, 22.1.8 Temperature of the calibration device and a statement that computed forces have been temperature corrected as necessary, 24. Keywords 24.1 calibration; force range; resolution; verification ANNEX (Mandatory Information) A1. VERIFYING THE FORCE MEASURING SYSTEM OUT OF THE TEST MACHINE A1.1 Significance and Use A1.1.1 The following are the recognized reasons to perform a force measuring system verification out of the test machine: A1.1.1.1 Inadequate spacing within the testing application load train to allow placement of a force standard. A1.1.1.2 Physically impossible to apply a primary deadweight force in the compression mode without removal of the force measuring system. A1.1.1.3 Test rigs have no reaction frame. A1.1.2 Verifying the force measuring system out of the testing machine represents an independent and singular uncertainty component of the total test machine system uncertainty. Other uncertainty components within the test machine system exist and need to be identified and quantified to determine, or verify, the test machine total performance and level of measurement uncertainty. For example, mounting considerations, 7 E 4 – 07 A1.3.2 A minimum of two runs is required per mode (compression or tension). Rotate the position of the force transducer by approximately 120 degrees before repeating any series of forces. During the verification, ensure that the loading axis is on the center load axis of the force applying apparatus. Introduce variations or any other factors that are normally encountered in service. A1.3.3 Repeatability between the two verification runs shall be less than or equal to 0.5%. If greater than 0.5%, an additional third verification run is required. The force transducer shall be rotated by approximately 240 degrees from the starting position prior to performing the third verification run. The repeatability between the three verification runs shall be less than 1.0%. Refer to A1.1.2 to consider all the uncertainty issues in determining the total test machine system uncertainty. A1.3.4 The percent error for forces within the verified range of forces of the testing machine system shall not exceed 6 1.0%. fixtures, hardness, stiffness, alignment, flatness, and bending may contribute to the measurement uncertainty of the test machine. A1.1.3 Fixture and environment considerations should be made, to the best degree possible, to simulate the environment within the testing application (for example, duplicating a preload). A1.1.4 Verifying the force measuring system out of the test machine can be performed: A1.1.4.1 On-site, removed from the test system, consisting of a complete force measuring system (force transducer, conditioning electronics, read-out devices, and cables). A1.1.4.2 Off-site, removed from the test system, consisting of a complete for measuring system (force transducer, conditioning electronics, read-out devices, and cables). A1.2 Calibration Devices A1.2.1 The force measuring system shall be calibrated by primary standards or secondary standards used over their Class A loading range in conjunction with a machine or mechanism for applying force (see Practice E 74). Several working standards of equal compliance maybe combined and loaded in parallel to meet special needs for higher capacities. A1.4 Calculation and Report A1.4.1 Verification of the force measuring system out of a test machine shall be clearly noted on the calibration certificate or report. A1.3 Verification A1.3.1 Out of test machine verifications shall include the force transducer, conditioning electronics, read-out devices, and cables. APPENDIXES (Nonmandatory Information) X1. DETERMINING RESOLUTION OF THE FORCE INDICATOR greater than those given in these exceptions, use the ratio determined. Typical ratios in common usage are 1:1, 1:2, 1:5, and 1:10. X1.3.3 Multiply the ratio determined above by the force represented by one graduation to determine the resolution. X1.3.4 Apply as constant a force as possible where the resolution is to be ascertained to minimize the fluctuation of the force indicator. It is recommended that the fluctuation be no more than twice the resolution determined in the previous step. X1.1 The resolution of a testing machine in general is a complex function of many variables including applied force, force range, electrical and mechanical components, electrical and mechanical noise, and software employed, to name a few. X1.2 A variety of methods may be used to check the resolution of the system. Some suggested procedures are as follows. X1.3 Procedure for Analog Type Force Indicators: X1.4 Procedure for Non-Auto-Ranging Digital Type Force Indicators: X1.4.1 The resolution should be checked at the lowest verified force in each force range (typically 10% of the force range). X1.4.2 Apply a tension or compression force to a specimen approximately equal to that at which the resolution is to be ascertained, and slowly change the applied force. Record the smallest change in force that can be ascertained as the resolution. Applying the force to a flexible element such as a spring or an elastomer makes it easier to change the force slowly. X1.3.1 Typically these devices are not auto-ranging. The resolution should be checked at the lowest verified force in each force range (typically 10 % of the force range). X1.3.2 Divide the pointer width by the distance between two adjacent graduation marks at the force where the resolution is to be ascertained to determine the pointer to graduation ratio. If the distance between the two adjacent graduation marks is less than 0.10 in. (2.5 mm) and the ratio is less than 1:5, use 1:5 for the ratio. If the distance between the two adjacent graduation marks is greater than or equal to 0.10 in. (2.5 mm) and the ratio is less than 1:10, use 1:10 for the ratio. If the ratio is 8 E 4 – 07 X1.5.1.3 A 1000 lbf. capacity machine is to be verified from 5 lbf. up to 1000 lbf. The resolution should be determined at 5, 50, and 500 lbf. X1.4.3 Next apply as constant a force as possible at the force where the resolution is to be ascertained to ensure that the force indicator does not fluctuate by more than twice the resolution determined in the previous step. If the indicator fluctuates by more than twice the resolution, the resolution shall be equal to one-half the range of the fluctuation. X1.6 Procedure for Machines with Discrete Forces Such as Certain Hardness Testers and Creep Testers: X1.6.1 These machines generally incorporate fixed lever ratios to apply force. The force applied is determined by the poise applied on the lever multiplied by the lever ratio. They do not have a resolution as described in the standard. This procedure ensures that the sensitivity of the machine is sufficient to apply accurate forces at the lowest verified force and may be substituted for reporting resolution. X1.6.2 With an elastic calibration device mounted in the machine, apply the appropriate poise for the lowest verified force. X1.6.3 Gently add weight to the poise approximately equal to 1/200 of the weight of the poise. X1.6.4 Ensure that at least one-half of the appropriate change in force is detected by the elastic calibration device when the weight is added and when it is gently removed. X1.5 Procedure for Auto-Ranging Digital Type Force Indicators: X1.5.1 This procedure is the same as that for non-autoranging digital force indicators except that the resolution is checked at the lowest verified force in each decade or at other forces to ensure that the indicator resolution is 200 times smaller than the forces. Some examples are as follows. X1.5.1.1 A 60 000 lbf capacity machine is to be verified from 240 lbf up to 60 000 lbf. The resolution should be determined at 240, 2400, and 24 000 lbf. X1.5.1.2 A 150 000 N capacity machine is to be verified from 300 N up to 150 000 N. The resolution should be determined at 300, 3000, and 30 000 N. X2. IDENTIFYING AND DETERMINING MEASUREMENT UNCERTAINTY COMPONENTS DURING AN ASTM E 4 VERIFICATION X2.1 The measurement uncertainty determined using this appendix is the measurement uncertainty of the errors reported during verification of a testing machine. It is not the measurement uncertainty of the testing machine or the measurement uncertainty of test results determined using the testing machine. environmental conditions allowed. It may be advantageous to evaluate the measurement uncertainty of the actual force standard used at the actual force for which the measurement uncertainty of the error of the testing machine is being determined. NOTE X2.2—If there are circumstances in which verification is performed under conditions outside of the laboratory’s normal operating parameters, additional components may need to be considered. For example, a laboratory may permit a 5°C temperature variation to occur during verification and has factored this into their measurement uncertainty. When greater temperature variations occur, the uncertainty due to this increased temperature variation shall be included in the determination of measurement uncertainty. NOTE X2.3—A calibration laboratory’s measurement uncertainty is usually expressed as an expanded uncertainty using a coverage factor of two. If this is the case, prior to combining it with the other uncertainty components, divide it by two. X2.2 Under normal conditions, the measurement uncertainty of the reported errors of a testing machine determined during an Practices E 4 verification is a combination of three major components: the measurement uncertainty of the calibration laboratory performing the verification, the uncertainty component of the resolution of the force indicator of the testing machine at the force the error is being determined, and the uncertainty component of the resolution of the force indicator of the testing machine at zero force. X2.2.1 The measurement uncertainty of the calibration laboratory performing the verification is a combination of factors such as, but not limited to: X2.2.1.1 The measurement uncertainty of the laboratory’s force standards per Practice E 74, X2.2.1.2 Environmental effects such as temperature variations, X2.2.1.3 Uncertainty in the value used for the local acceleration of gravity at the site where the verification is performed when using standard weights, X2.2.1.4 Drift in the force standard, X2.2.1.5 Measurement uncertainty of the verification of the force standard, and X2.2.1.6 Repeatability of the force standard in actual use. X2.2.2 The uncertainty component due to the resolution of the force indicator of the testing machine being verified can be determined by dividing the resolution of the force indicator at the force where uncertainty is being evaluated by the quantity of two times the square root of three. X2.2.3 The uncertainty component due to the resolution of the force indicator of the testing machine at zero force can be determined by dividing the resolution of the force indicator at zero force by the quantity of two times the square root of three. X2.3 The three major components can be combined by squaring each component, adding them together, and then taking the square root of the sum to determine the combined measurement uncertainty of the error determined for the testing machine. X2.4 The expanded measurement uncertainty may then be determined by multiplying the combined uncertainty by two, for a confidence level of approximately 95 %. NOTE X2.1—A laboratory’s measurement uncertainty should be based on the maximum uncertainty of the force standards used and the worst 9 E 4 – 07 NOTE X2.4—Example: The measurement uncertainty of the error of a testing machine determined at 2000 N is to be determined. The calibration laboratory’s measurement uncertainty expanded using a factor of 2 is 0.3 % of applied force. The testing machine’s resolution at 2000 N is 5 N. The resolution of the testing machine at 0 force is 5 N. The component due to the calibration laboratory’s measurement uncertainty, uCL is: 0.003 3 2000 uCL 5 53N 2 uZ 5 5 2=3 5 1.4 N (X2.3) The combined measurement uncertainty of the error determined at 2000 N, u is: u 5 =32 1 1.42 1 1.42 5 3.6 N (X2.1) (X2.4) The expanded measurement uncertainty of the error determined at 2000 N, U using a coverage factor of two is: The component due to the testing machine’s resolution at 2000 N, uR2000 is: uR2000 5 5 5 1.4 N 2=3 U 5 2 3 3.6 5 7.2 N (X2.2) (X2.5) NOTE X2.5—For additional resources relating to Measurement Uncertainty, refer to the Guide to the Expression of Uncertainty in Measurement–1995. The component due to the testing machine’s resolution at zero force, uZ is: ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility. This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards, at the address shown below. This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at 610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website (www.astm.org). 10 Lab of Mechanics of Materials LAB 2 Data Sheet Reading Machine Proving ring No. load (lb) reading (PR) 1 2 3 4 5 6 7 Note: 0 10000 20000 30000 40000 50000 0 the reading from the controller Adjusted PR Temp. Adj. PR, d23 Actulal load Error (lb) (lb) Error (%) Col (F) = Col (E) * CF Use ASTM E4 Absolute stnd. value of [Error/Actual error ) = Col G/Col F Abs (Error) (lb) 1% error 2% error (lb) (lb) 0 0 the reading from the ring (Actual) Initial Zero (no) load PR =1 Final Zero (no) load PR =2 Average of Zero (no) load PR =1.5 Calibration Factor (CF) = 138.5 Temperature = 27 oC Col (D) = Col Col (E) = [apply the (C) - the formula for temp.] average PR of zero (no) load Use ASTM E4 stnd [MachineActual) = Col B- Col F Actual Load *1.01 Actual Load * 1.02 machine load (lb) 0 9000 18500 28000 37800 49000 0 proving ring reading zero error adjust temperature corrected (PR) PR PR, d23 0 0 0.0 43 43 43.0 128 128 127.9 189 189 188.8 267 267 266.7 334 334 333.6 0 o d23 = dt – 0.00027 (t – 23) dt machine load vs. actural load Machine Load, lbf 60000 y = 1.019x + 1079.1 R² = 0.996 50000 40000 30000 20000 10000 0 0 errors vs. 1% vs. 2% 10000 20000 30000 Actual Load, lbf 40000 50000 actulal load 1% error (lb) error (lb) error (%) (lb) 0.0 0.0 0.0 5964.1 3035.9 50.9 59.6 17753.6 746.4 4.2 177.5 26214.3 1785.7 6.8 262.1 37032.9 767.1 2.1 370.3 46325.8 2674.2 5.8 463.3 0 0 0 2% error (lb) 0 -59.6 -177.5 -262.1 -370.3 -463.3 0.0 0 119.3 355.1 524.3 740.7 926.5 0 0 -119.282 -355.0721 -524.2862 -740.6582 -926.5163 0 3500.0 3000.0 2500.0 2000.0 1500.0 1000.0 500.0 0.0 -500.0 50000 -1000.0 -1500.0 0.0 5000.0 10000.0 15000.0 20000.0 25000.0 Series6 1% -1% Error (lb) 0 3035.9 746.4 1785.7 767.1 2674.2 0 0 9000 zero error 18500 28000 37800 49000 0 25000.0 30000.0 35000.0 40000.0 45000.0 50000.0 2% 2% error (lb) 2.1 2.1 CF = 2.1 2.1 2.1 2.1 2.1 138.85 Laboratory 2 Calibration of UTM Using Morehouse Proving Ring This lab will use a Morehouse Proving Ring to check the accuracy of the Tinius & Olsen (T&O) Universal Testing Machine (UTM). Read and study the instructions for using Morehouse Proving Rings and the ASTM Standards on Verification of Testing Machines. Write the procedure as per the ASTM Standards for the verification of the T&O Universal Testing Machine using the Morehouse Proving Ring. CAUTION: the maximum indicated load on the machine should not exceed 50,000 pounds. Determine and/or include the following in the report: • type of verification device ( Proving Ring ). • capacity of the T&O machine ( 50,000 lb ). • capacity of the proving ring ( 100,000 lb ). • accuracy of the proving ring calibration • table showing ring readings, calibration factor, proving ring load, indicated machine load, error in pounds, and error in percentage • graph of error in pounds vs. proving ring load, show 1% and 2% error lines [will determine the accuracy level of the UTM] • plot of actual load (y-direction) vs. indicated load (x-direction) [linear regression will provide calibration equation for the UTM] • comments on T&O machine based on % of error An equation for the calibration factor should be derived so that it can be used instead of reading values from the given graph. Readings will be taken from the Proving Ring at loads of 10k, 20k, 30k, 40k, and 50k. In addition, two no-load readings will be taken (before and after loading for test). The report should be written to the instructor in such a way as to meet the following objectives: 1) determine the magnitude of error in the loads indicated by the machine from 10k to 50k pounds, 2) determine if the errors are within ranges accepted by ASTM, and 3) prepare a calibrations chart (graph) of Proving Ring Load vs. Machine Gage Reading Load. Findings should be discussed as well as recommendations for any action(s) that should be undertaken. Appendix should contain 1) Calibration data of Testing Equipment 2) Certification of Calibration of Morehouse Proving Ring Testing Procedure for T&O Testing Machine Verification 1. Make sure all items are off the table and the machine is ready for start-up. 2. Then, Power ON; wait for “clicking” to stop before proceeding any further. 3. Zero the “LOAD” and “UNLOAD” knobs in the lower left-hand side. 4. Turn Pump ON. Allow machine to warm up for about 15 minutes. 5. Switch to Manual Control. Make sure that the Lower Head is in an approachable position. 6. Leave machine in ‘FAST’ mode to Zero table. Switch to ‘SLOW’ for Experiments. 7. Zero all Channels. Verify proper range on loading. 8. Depress “LOAD” and rotate “LOAD” knob to approx. 70 (up to 100 is OK) to raise table to 6” according to readout. 2” is Fine. 9. Decrease “LOAD” to zero. Then hit STOP. 10. Press and hold “FAST UNLOAD” to allow table to return to neutral position. 11. When pitch of motor changes, then release “FAST UNLOAD” button and allow table to return to equilibrium. 12. Switch to “SLOW”. 13. Re-Zero all channels and reset Max load with the “CLEAR” button. 14. Place Proving Ring on the table; center is approximately. 15. Obtain “Temperature” and “No-Load” reading. Rotate dial away from reed 4 revolutions. 16. Lower the lower head to close to top of the Proving Ring. . 17. Verify that knobs are at Zero and press “LOAD”. 18. Increase load slowly until Ring contacts lower head. Approx. 20% should be sufficient. 19. Once load starts registering, watch only the load reading. 20. Monitor Proving Ring during loading to ensure reed clearance. 21. Reduce loading rate when the desired load is approached. Null range is at approx. 12 on the dial. 22. At desired load(s), take reading on the ring dial while another maintains static load. 23. Once all loads have been recorded (from Ring and machine), prepare to unload. 24. To unload, decrease “LOAD” dial to zero. If unloading stops, press “STOP.” Then press “UNLOAD” and increase “UNLOAD” dial until ring is unloaded. 25. When table movement (down) is observed, press “STOP.” 26. Obtain ‘NO-LOAD’ reading from Proving Ring and Machine. 27. Remove Ring from the machine and return it to the cabinet. 28. Depress “FAST UNLOAD” to allow table to return to neutral position. 29. Shut OFF machine. Calibration of Testing Equipment A. General 1. ASTM provides procedures for calibration & verification of equipment a) ASTM E4 – Standard practices for load verification of testing machines b) ASTM E83 – Standard method of verification and classification of extensometers. “Extensometer – an instrument for measuring strain in tension tests.” c) ASTM E74 – Standard practice of calibration of force – Measuring instrumentations for verifying the load indication of testing machine. 2. Calibration – The procedure of determining the magnitude of error in the indicated loads. 3. Verification – a calibration to ascertain whether the errors are within a predetermined range. A certification can be given if errors are acceptable. 4. Load verification must be performed at least every 18months if the machine is to be used for reporting test data. a) Always perform after relocation b) After making a repair c) Or when accuracy is suspected B. Verification Methods 1. ASTM E4 allows standard weights, standard weights and lever balances, or elastic calibration devices. 2. At least 5 verification load levels must be used. o Minimum is 10% of machine load range. o Increment between loads must be less than 1/3*(max. load – min. load) 3. Testing machine must be accurate to within ±1% of the actual load for all reading. 4. If deviations are >1%, the machine should be repaired or adjusted to read correctly. C. Elastic Calibration Devices 1. Two devices are common: elastic proving ring and strain-gage load cell. 2. Proving Ring: a) Made of flawless forged steel ring and has a deflection gage or dial. b) Rign has a uniform and repeatable deflection throughout load range. c) Only used in compression tests. 3. Strain-gage load cells: a) May be used in either compression or tension tests. b) Accuracy ≒ ±0.05% Morehouse Proving Ring A. General 1. We have Ring No. 4058 with a capacity of 100,000 lb. 2. Ring Reading – the value indicated by the single line index or vernier on the micrometer dial. 3. Deflection – The difference between the proving ring reading taken under load and the no load reading. 4. Temp. Correction: The ring calibration factor is dependent on temperature. We have a curve for 23℃. (Please see the figure attached.) B. Calculation of Actual Loading at room temperature (for 27℃) 1. Determine dial reading at no load before and after tests, say 1.8 and 1.9 o So average no load reading(NLR) = 1.85 2. Determining dial reading under load specified by machine. o Say reading = 215 → dt = 215 - 1.85 = 213.15 3. Calculate d23 since Temp at test was 27℃. o d23 = dt – 0.00027 (t – 23) dt o d23 = 213.15 – 0.00027(27-23)(213.15) = 212.92 4. From the chart, Calibration factor (CF) corresponding to the number of deflection division (500) is o CF = 138.85 5. Actual Load (From the deflection of the ring) = CF * d23 = 138.85 (212.92) =29,564 lb 6. % Error o (Machine Load – Ring load) / Ring Load * 100 Fall 2018 ENGR 2411 Mechanics of Materials Lab Section No. 00X (where X=1, 2 or 3) Lab No. Lab Title: Submitted to: Dr. Hyunju Jeong Submitted By: Name: Student ID: 1 TABLE OF CONTENTS Title List of Tables List of Figures Abstract Introduction Background and Methodology Results and Discussions Conclusions and Recommendations References Cited Appendix A Raw Data Appendix B Detail Calculations Pg. No. 3 4 5 5 5 6 6 6 7 7 2 List of Tables Table No. and Title Table 1 Format and Layout of Tables Pg. No 5 3 List of Figures Figure No. and Title Figure 1. Representative graphics embedded within the format of the paper. 4 Pg. No 6 ABSTRACT INTRODUCTION METHODOLOGY RESULTS AND DISCUSSIONS 5 Figure 2. Representative graphics embedded within the format of the paper. CONCLUSIONS AND RECOMMENDATIONS REFERENCES CITED Brown, D.Z. and Vinson, R.J. (2006). "Stiffness parameters for a strong and colorful aeolian soil." Geomaterial Characterization (GSP 199), ASCE, Reston/VA: 12-22. Cimponella, G.R. and Rubertsen, K.P. (1999). "Common problems with conventional testing." J. Geotechnical & Geoenv. Engr., Vol. 181 (9): 1193-1199. APPENDIX A RAW DATA APPENDIX B SAMPLE CALCULATIONS < Attach sample calculations> 6
Purchase answer to see full attachment
User generated content is uploaded by users for the purposes of learning and should be used following Studypool's honor code & terms of service.

Explanation & Answer

Attached.

1

Lab Report: Calibration of UTM Using Morehouse Proving Ring
Student name:
Institutional affiliation:

2
Calibration of UTM Using Morehouse Proving Ringt
The attached word document addresses the question “Lab Report” as follows:
Abstract
Introduction
Methodology
Results
Discussion
Conclusion and recommendation


1

Running Head: Calibration of UTM Using Morehouse Proving Ring

Lab Report: Calibration of UTM Using Morehouse Proving Ring
Student name:
Institutional affiliation:

2

Calibration of UTM Using Morehouse Proving Ring

List of tables and figures
Figure 1: Proving Ring and its elements
Table 1: Experimental Results
Figure 2: Machine Load vs. Actual Load
Figure 3: error vs. 1% vs. 2 %

3

Calibration of UTM Using Morehouse Proving Ring
Abstract
The purpose of this experimental study was to obtain readings from More House Proving
Ring and Tinius Olsen Universal Testing machine ( UTM). Moreover, an analysis is carried out
the readings obtained so as to ascertain if they conform with the American Society of the
International Association for Testing and Materials (ASTM) . According this experiment study,
the UTM used did not achieve ASTM standards. According to the ASTM standards, the UTM is
not supposed to exceed an error of +1% when the actual load is imposes. We observed that our
first instant resulted to an error of -1.75%. Therefore, this machine can only meet standards if it is
calibrate correctly.

4

Calibration of UTM Using Morehouse Proving Ring
Calibration of UTM Using Morehouse Proving Ring
Introduction
The main objective of this experiment was to use a Morehouse Proving Ring to check the
accuracy of the Tinius & Olsen (T&O) Universal Testing Machine (UTM). Typically, the
experiment was seeking to to test the accuracy achieved using our study UTM as compared with
the specific ASTM standards. In order to achieve verification, the processs of calibrating an elastic
proving ring were perform. After carrying out the necessary mathematical analysis and effectively
executing the experiment, a recommendation will be made on whether it was necessary to calibrate
the machine or that the standards of the machine fall under the acceptable accuracy range.
It is worth notin...


Anonymous
Really great stuff, couldn't ask for more.

Studypool
4.7
Trustpilot
4.5
Sitejabber
4.4

Similar Content

Related Tags