Experiment 1_Full Lab Report_Group A_v1.1

7/24/2019 Experiment 1_Full Lab Report_Group A_v1.1

1/24

EGME 306A The Stress-Strain Relationship in Tension

Group A Page 1 of 24

306A-Unified Laboratory

The Stress-Strain Relationship in Tension

Oscar Rosales

Christian Lugo

Michael Gooneratne

Todd Yeakley

Mina Alad Al Malak

Tony Cardenas

Due: September 24, 2015

Submitted: September 23, 2015


2/24



Abstract

A group was formed with the goal of determining the mechanical properties of standardized metal

bars under tension using the MTS Insight Tensile Testing machine in order to obtain stress-strain diagrams

for each sample. After completing testing, the mechanical properties of the standardized metals were

shown through the variables of: stress, applied load, area, strain, elongation and original length. The stresses

produced were: 1018 yielded 531.2554 Pa, 1045 yielded 846.0902 Pa, and 6601 yielded 512.9905 Pa. Thestrains produced were: 1018 yielded 6.5475E-06 Pa, 1045 yielded 6.2575E-06Pa, and 6601 yielded 6.5875E-

06 Pa. The percent area reduction proved all to be less than 60%. The results were as expected due to the

procedures taking place amongst the metals, but may be explained by the amount of stress and strain on

each metal.


3/24



Table of Contents

List of units

Introduction and Theory ..5

Procedure and Experimental Set- up .6

Results

Sample Calculation and Error Analysis

Discussion and Conclusion

References

Appendix


4/24



List of Symbols and Units

Name Symbol UnitDisplacement inches

Strain Unit lessStress PascalLoad P PoundsArea A Inches squared

Diameter D InchesLength L inches


5/24



Theory

Tensile tests are used to characterize the properties of mechanical behavior on materials. Therefore,

metal bars were subjected to an infinite load. This load would be indirectly proportional to the area given,

hence giving a stress. Furthermore, an elongation was exposed and indirectly proportional to the original

length of the metal bars, which gave way for the strain of the materials. Since the metals were rendered to a

tensile test, elasticity took place. After a certain degree of stress, the material elongates causing elasticity.

For the equation of elasticity, stress was indirectly proportional to the strain of the given materials. To

equate all these behaviors, variables were applied to the formulas of:

= , = , and = .


6/24



Procedure and Experimental Set up

The procedure for this lab is modeled after the procedure section in the lab manual; refer to it for

more detail. (Mechanical Engineering Department)

The key areas utilized on the MTS insight tensile testing machine are shown below in Figure 1.

Figure 1: Key areas on the MTS Insight Tensile Testing Machine, labeled A-J.

Figure 1-A Emergency Stop button.

Figure 1-B Power Switch.

Figure 1-C Extensometer connector cradle.

Figure 1-D Lower Jaw Handle.

Figure 1-E Lower Jaw.Figure 1-F Test Sample with Installed Extensometer.

Figure 1-G Upper Jaw.

Figure 1-H Upper Jaw Handle.

Figure 1-I Load Sensor.

Figure 1-J MTS Handset.


7/24



The following is the procedure for this lab, and the importance that each step has. The lab is begin

by going over the lab and techniques for using the equipment in class and reading the procedure list

provided in the lab manual. Once it is understood what to do and how to do it, it is time to move onto

physically beginning the lab. First by checking all major systems and connections to make sure everything

has good connectivity and all systems and switches are in a go position to successfully complete theexperiment. These things include making sure the Emergency Stop switch (Figure 1-A) on the MTS frame is

off by twisting it to pop up, which insures the systems fail safe is disengaged for the following steps, and

should only be engaged during an unplanned failure. Once this check is complete, the system is turned on

by using the power switch next to the emergency stop (Figure 1-B)

Three samples are then taken out of the upper left desk drawer and a note is added on the data

recording sheet which color-coded sample will be tested. With the samples in hand, using calipers, the

diameter is measured in three places to find a nominal value and use a length value of 2 inches is used

because that is what the extensimeter can measure. The precision with which the calipers can measure the

diameter is also noted for future reference.

Moving over to the computer desktop, click on the TestWork 4 on the Windows desktop to open

the data acquisition software. Once the program is in operation, the motor is zeroed by pressing the Motor

Reset t owards the bottom of the screen.

The jaws are then adjusted using the hand controller on the machine (Figure 1-J) in order for the

test sample adequate clearance to fit 1. A test sample is then chosen and a note of the material type is

documented. The sample is then inserted into the upper jaws of the machine (Figure 1-G), leaving at least a

inch gap between the bottom of the jaw and the sample. When securing the sample it is important that

the jaws are not over tightened while using the t-handles (Figure 1-H) although the sample be securely in

the jaws. Lower the jaw and repeat this for the lower jaw (Figure 1-E), still making sure not to overtighten

the jaws using the t-handles (Figure 1-H). Once the sample piece is securely in place, return control to the

computer station by pressing the lock button on the hand controller and place the hand controller back in

place on the side of the machine.

With the sample now firmly in place, attach the extensometer so that the blades of the

extensometer are placed against the test section as close to the middle as possible. Then secure the

extensometer to the specimen using the clips. Make sure the extensometer connector is securely seated in

the cradle (Figure 1-C) to ensure cable tension is not affecting the reading. Once everything is placed and

1 To transfer control to the handset, press the lock button on the handset until


8/24



secure, remove the safety pin, then on the computer, zero all the information about the load 2, crosshead,

and extensometer by right- clicking on each area dedicated to these items and selecting zero channel.

For the first sample run, it is important to call an instructor over to the station to check the set up

and once everythi ng is approved, click the Green Arrow on the scr een to begin the experiment. When

prompted type-in the data which include the material name, group number, and the average samplediameter. Once this information is given to the machine, click okay in the dialog to begin the experiment.

Once the test piece has broken, it is important to follow the on-screen instructions and remove the

extensometer before clicking OK on the dialog. When it has been removed, re -insert the black pin. When

the extensimeter is removed and properly placed in a storage position, click OK on the dialog box on the

computer. Using the extensimeter reading, a final length is recorded and using calipers measure a cross-

sectional diameter of the specimen. Once all sections are reset and data gathering is complete, store the

data by going into the menu and give the file an appropriate name and select save. When the data is saved

as a proprietary file for safe keeping, export the data by going to File > Export Preview> Specimen. Follow

this by giving the file a name and save the data in a place that is easily accessible. Because the information

is stored in a comma text format, the information must be imported into excel to be able to make use of the

data. Once imported into excel, save the numerical results for the test on the desktop and on a USB flash

memory drive. Since the output file is in a comma-delimited format where the first and forth columns of the

data giving the information on the load and extension. This file should be imported into Excel, by opening

the text file from within Excel then saved as an Excel file. Lastly take note of the resolution of the load

meter (Figure 1-I) and extensimeter. Then repeat these steps until all samples have been tested. To ensure

a fresh data start on the computer, it is advised to open a new recording dialog by going to File > New

Sample.

2 The load gauge is shows in Figure 1-I.


9/24



Results

Steel 1018


10/24



Steel 1045

0.0000

20000.0000

40000.0000

60000.0000

80000.0000

100000.0000

120000.0000

0.00000 0.01000 0.02000 0.03000 0.04000 0.05000 0.06000

S t r e s s

( P s i )

Strain(In/In)

Stress vs. Strain - Elastic RangeRed Bar 1045 Steel

0.0000

10000.0000

20000.0000

30000.0000

40000.0000

50000.0000

60000.0000

70000.0000

80000.0000

0.00000 0.00050 0.00100 0.00150 0.00200 0.00250 0.00300

S t r e s s

( P s i )

Strain(In/In)

Stress vs. Strain - Elastic RangeRed Bar 1045 Steel


11/24



Aluminum 6061-T6

0

5000

10000

15000

20000

25000

30000

35000

0 0.0005 0.001 0.0015 0.002 0.0025 0.003 0.0035

S t r e s s

( P s i )

Strain(In/In)

Stress vs. Strain - Elastic RangeGreen Bar - Aluminium

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18

S

t r e s s

( P s i )

Strain(In/In)

Stress vs. StrainGreen Bar - Aluminium


12/24



Sample Calculation and Error Analysis

Error in Stress

= =4 =4

=48272.132 (.3413) =90418.0211 =(, )

=| |+| | =4 = 8

=4 +8 =(. )(.001 )+( . )(. ) (.001 )

=531.2554 PaError in Strain

= =.00619

2=.003095 /

= ( , ) =| |+| |

=1 =

=1 += 12.000(.00001)+.00619(2.000)(.001) =6.547510


13/24



Error in Elastic Modulus

= =531.2554 .003095

=29167103.58 = ( , ) =| |+| |

=1 =

=1 + = 1.003095(531.2554)+90418.02(.003095) (6.547510)

=232,976.5 Percent Area Reduction

% =100% =100%.341.221.221

=57.997%

Material (psi) (in/in) E (psi) % Area Reduction (%)

1018 Steel 531.2556.5475E-

06 232976.5 57.997

1045 Steel 846.09

6.2575E-

06 403774.2 34.123

6061 Aluminum 512.9916.5875E-

06 181425.1 60.802


14/24



Discussions and Conclusions

The experiments data was recorded to the tenth point to insure that it is as accurate as possible. It

was calculated into stress and strain using equation 1 and 2 which is shown in data tables 1, 2, and 3. The

data was then graphed and analyzed. The stress has an uncertainty of 0.5312554 Kpa which is 0.08 psi.

This error is from measuring error with the computer force and error in the area from the caliper

measurements. The error from the strain was measure at 6.5475 10 in/in. The error comes from theerror in the extensometer.

The steel 1018 data was graphed on Stress vs. Strain Blue Bar 1018 Steel graph which shows an

elastic region up to 10000 psi and then it turns into the plastic region. It also shows that the ultimate

strength is 10957.0184 psi. Also for steel 1045 from the Stress vs. Strain Red Bar 1045 Steel graph, the

elastic region goes up to 75000 psi and has an ultimate strength of 113579.7611 psi which shows that steel

1045 is clearly stronger. Aluminum 6061 has an elastic region that ends at 32500 psi and an ultimate

strength of 39649.86364 psi.

The modulus of elasticity from Stress vs. Strain - Elastic Range Blue Bar 1018 Steel graph for 1018

steel is 24269.67 ksi and the theoretical value is 29700 ksi. The difference can be attributed to an error is the

different measurements of the diameters from the top, bottom and middle of the specimen and having

different readings. The modulus of elasticity of 1045 steel from the Stress vs. Strain - Elastic Range Red Bar

1045 Steel graph is 27448.915 ksi. The provided value 29000 ksi which shows that the values are very close.

The modulus of elasticity of Aluminum 6061 is 9568.8 ksi and the provided values is 10000 ksi. The

difference can be attributed to an error is measuring the extensometer or an error in excel from rounding.For all three specimens, the rods had a cup shape on one side and a cone shape on the other after breaking

apart.

As shown in this experiment, under tension, the metal acts as linearly until it reaches its proportionality

limit. Once entering the plastic regions the material increases to the ultimate strength and then falls off until

it reaches the breaking point. The material necks severely, up to 57.997% in the case of 1018 steel, and

breaks.


15/24



References:

1. Mechanical Engineering Department. "Experiment 1 The Stress-Strain Relationship in Tension."

Fullerton: California State University Fullerton, n.d. Print. September 2015.

2. "AISI 1018 Mild/Low Carbon Steel." AISI 1018 Mild/Low Carbon Steel . N.p., n.d. Web. 24 Sept. 2015.

3. "AISI 1045 Medium Carbon Steel." AISI 1045 Medium Carbon Steel . N.p., n.d. Web. 24 Sept. 2015.

4. "ASM Material Data Sheet." ASM Material Data Sheet . N.p., n.d. Web. 24 Sept. 2015.


16/24



Appendix:

Appendix-1

Steel 1018:

Strain(In/In) Stress(Psi) modulus of elasticity est (Psi)

0.00000 0.0000

0.00019 5521.7072 29061616.8947

0.00030 8739.7264 29254719.5458

0.00037 11033.8284 35293877.9437

0.00044 12991.6774 27969271.7146

0.00050 14936.9674 32421499.1238

0.00056 16963.2191 31173103.0368

0.00064 19062.5954 27991684.3163

0.00070 21212.2518 33071635.9362

0.00078 23412.8439 27507402.1778

0.00085 25644.5660 31881743.7142

0.00094 27927.1036 26853384.2771

0.00102 30223.3044 28702508.8791

0.00109 32563.1831 33426839.1179

0.00117 34924.3434 27778356.4695

0.00125 37320.9730 29957869.61660.00134 39728.7516 28326807.2411

0.00141 42141.4926 32169880.4545

0.00149 44564.3990 30286329.2610

0.00158 47030.1417 29008737.9427

0.00166 49519.6581 31118955.3314

0.00174 52015.1426 29358640.5335

0.00183 54523.3282 27868729.0403

0.00191 57028.8358 31318845.7057

0.00200 59536.2782 27860470.4876

0.00209 62060.9250 28051631.6931

0.00217 64584.4242 33646655.4193

0.00226 67112.6999 28091952.8622

0.00234 69668.5750 30069118.9657


17/24



0.00243 72218.7007 28334730.0222

0.00252 74765.0117 28292344.2149

0.00261 77341.2175 30308302.6551

0.00270 79942.0822 28898497.6944

0.00279 82537.0883 28833400.86720.00288 85173.4005 27750654.7479

0.00299 87801.7991 23894532.4033

0.00310 90418.0211 24916400.5436

0.00324 93019.1811 18579713.6736

0.00343 95549.0089 13314883.5774

0.00370 97887.8165 8504754.7468

0.00412 99991.0513 5007701.8289

0.00476 101784.8563 2824889.7878

0.00565 103128.7536 1509996.9445

0.00695 103779.3004 498503.3286

0.00867 103913.3731 77949.2706

0.01053 103957.0184 23465.1810

0.01246 103918.6198 -19947.3385

0.01444 103694.3272 -113279.0787

0.01649 103345.2418 -170285.5511

0.01861 102736.8974 -286954.9174

0.02078 102016.0897 -331405.8371

0.02299 101113.1481 -408570.8481

0.02522 100187.6024 -415975.6040

0.02746 99185.1829 -446512.0202

0.02972 98225.6435 -425516.3544

0.03197 97182.2458 -463732.3089

0.03422 96189.9042 -440062.8035

0.03648 95172.7724 -450058.3425

0.03874 94152.1756 -451591.5056

0.04099 93127.9280 -455221.1417

0.04326 92049.9682 -474872.1314

0.04553 90993.7929 -466302.5945


18/24



0.04781 89890.9882 -483686.2379

0.05010 88770.2358 -489411.5287

0.05239 87638.8481 -494055.7713

0.05470 86443.8125 -517331.4517

0.05700 85220.1719 -530863.60440.05933 83964.4941 -540076.4388

0.06167 82681.6762 -548212.8190

0.06400 81324.7935 -582353.0645

0.06637 79939.7978 -584386.3820

0.06875 78484.9456 -610000.9018

0.07116 76933.4793 -645100.3273

0.07358 75324.3550 -664927.4151

0.07603 73637.0890 -687277.4101

0.07851 71837.7094 -725556.2655

0.08104 69895.9281 -769022.2879


19/24


20/24



0.00615 0.00308 77847.4708 14423003.9901

0.00661 0.00331 80697.2363 12390284.5364

0.00711 0.00356 83464.6419 11069622.2683

0.00768 0.00384 86192.0646 9569904.2812

0.00832 0.00416 88774.5944 8070405.59680.00902 0.00451 91270.8288 7132098.5066

0.00982 0.00491 93678.1793 6018376.1346

0.0107 0.00535 95971.0878 5211155.7561

0.01167 0.00584 98111.8760 4413996.2170

0.01276 0.00638 100199.8724 3831186.1325

0.01393 0.00697 102114.9191 3273584.0811

0.01522 0.00761 103867.5654 2717281.0839

0.01663 0.00832 105542.0417 2375143.6059

0.01814 0.00907 107049.6135 1996783.8385

0.01981 0.00991 108418.7267 1639656.5679

0.02167 0.01084 109647.5408 1321305.5297

0.02369 0.01185 110679.1641 1021409.1986

0.02591 0.01296 111569.1416 801781.5057

0.02835 0.01418 112289.9551 590830.7521

0.03098 0.01549 112836.6517 415738.8585

0.03389 0.01695 113276.8072 302512.3573

0.03702 0.01851 113497.7454 141174.5363

0.0404 0.02020 113579.7611 48530.0074

0.04401 0.02201 113492.9420 -48099.1917

0.04787 0.02394 113163.7569 -170562.2400

0.05194 0.02597 112645.5062 -254668.6578

0.05615 0.02808 111890.7252 -358565.7868

0.06045 0.03023 110993.0115 -417541.2434

0.06478 0.03239 110039.7379 -440311.1639

0.06917 0.03459 109059.2753 -446680.0020

0.07353 0.03677 108084.2444 -447261.8362

0.07792 0.03896 107094.0405 -451117.9655

0.08232 0.04116 106034.3604 -481672.7801


21/24



0.08674 0.04337 104947.4913 -491795.9505

0.09118 0.04559 103826.7446 -504840.8704

0.09565 0.04783 102662.0048 -521136.3914

0.10009 0.05005 101443.0367 -549084.7150

0.10464 0.05232 100124.7400 -579471.08210.10921 0.05461 98711.0800 -618669.5805

0.11385 0.05693 97149.9085 -672918.7749


22/24



Appendix-3

Aluminum 6061-T6

Load (lbf) Filter Time (s)

Crosshead

(in)

Extensometer

(in) Strain(In/In) Stress(Psi)

modulus of elasticity

est (Psi)

0 0 0 0 0 0 0523.353 0 16.1 0.008 0.00114 0.00057 5604.931668 9833213.453

758.824 0 32.1 0.016 0.00165 0.000825 8126.745559 9889466.236

962.505 0 48.1 0.024 0.00211 0.001055 10308.09942 9484147.221

1175.026 0 64.1 0.032 0.00259 0.001295 12584.12666 9483446.825

1395.762 0 80.1 0.04 0.00307 0.001535 14948.13374 9850029.495

1622.688 0 96.1 0.048 0.00358 0.00179 17378.4336 9530587.695

1855.265 0 112.1 0.056 0.0041 0.00205 19869.25374 9580077.461

2093.113 0 128.1 0.064 0.00463 0.002315 22416.52449 9612342.443

2336.718 0 144.1 0.072 0.0052 0.0026 25025.45073 9154127.189

2584.062 0 160.1 0.08 0.00574 0.00287 27674.42039 9810998.742

2836.768 0 176.1 0.088 0.00635 0.003175 30380.81524 8873425.727

3035.615 0 192.1 0.096 0.00834 0.00417 32510.39862 2140284.798

3114.045 0 208.1 0.104 0.01395 0.006975 33350.3571 299450.4388

3164.985 0 224.1 0.112 0.02036 0.01018 33895.90708 170218.4028

3205.243 0 240.1 0.12 0.02669 0.013345 34327.05649 136224.1433

3238.329 0 256.1 0.128 0.03271 0.016355 34681.39624 117720.8459

3269.056 0 272.1 0.136 0.03834 0.01917 35010.4719 116900.7683

3296.452 0 288.1 0.144 0.04364 0.02182 35303.87369 110717.6573

3322.758 0 304.1 0.152 0.04872 0.02436 35585.60196 110916.6396

3347.335 0 320.1 0.16 0.05364 0.02682 35848.81322 106996.4495

3370.951 0 336.1 0.168 0.05843 0.029215 36101.73251 105603.0415

3392.923 0 352.1 0.176 0.06319 0.031595 36337.04511 98870.84312

3413.742 0 368.1 0.184 0.06789 0.033945 36560.00948 94878.4557

3434.625 0 384.1 0.192 0.0726 0.0363 36783.65927 94968.06328

3455.681 0 400.1 0.2 0.07731 0.038655 37009.16183 95754.80249

3475.552 0 416.1 0.208 0.08203 0.041015 37221.97345 90174.41317

3495.138 0 432.1 0.216 0.0868 0.0434 37431.73281 87949.41825

3514.092 0 448.1 0.224 0.09161 0.045805 37634.72367 84403.68343


23/24



3533.151 0 464.1 0.232 0.09647 0.048235 37838.83904 83998.09578

3550.233 0 480.1 0.24 0.10136 0.05068 38021.78142 74823.0588

3566.428 0 496.1 0.248 0.10634 0.05317 38195.22433 69655.78799

3582.793 0 512.1 0.256 0.11137 0.055685 38370.48789 69687.2978

3598.823 0 528.1 0.264 0.11648 0.05824 38542.16371 67192.101183613.594 0 544.1 0.272 0.12167 0.060835 38700.35606 60960.44664

3627.81 0 560.1 0.28 0.12697 0.063485 38852.60456 57452.2637

3642.15 0 576.1 0.288 0.13237 0.066185 39006.18106 56880.18385

3654.033 0 592.1 0.296 0.13788 0.06894 39133.44393 46193.418

3665.261 0 608.1 0.304 0.14353 0.071765 39253.69197 42565.67808

3675.862 0 624.1 0.312 0.14931 0.074655 39367.22505 39284.80449

3685.457 0 640.1 0.32 0.15527 0.077635 39469.98422 34482.94261

3692.658 0 656.1 0.328 0.16146 0.08073 39547.10447 24917.68905

3698.582 0 672.1 0.336 0.16787 0.083935 39610.54848 19795.32427

3702.253 0 688.1 0.344 0.17461 0.087305 39649.86364 11666.21801

3700.522 0 704.1 0.352 0.18167 0.090835 39631.32522 -5251.67651

3691.348 0 720.1 0.36 0.18904 0.09452 39533.07482 -26662.25317

3674.427 0 736.1 0.368 0.19677 0.098385 39351.85669 -46886.96606

3646.581 0 752.1 0.376 0.20472 0.10236 39053.63555 -75024.18566

3608.477 0 768.1 0.384 0.21286 0.10643 38645.55474 -100265.5553

3559.136 0 784.1 0.392 0.22114 0.11057 38117.12951 -127638.9463

3501.104 0 800.1 0.4 0.22951 0.114755 37495.62663 -148507.2583

3434.491 0 816.1 0.408 0.23797 0.118985 36782.22418 -168653.0618

3358.881 0 832.1 0.416 0.24649 0.123245 35972.46693 -190083.8603

3274.966 0 848.1 0.424 0.25508 0.12754 35073.76598 -209243.5285

3183.008 0 864.1 0.432 0.26377 0.131885 34088.92724 -226660.2382

3082.932 0 880.1 0.44 0.27252 0.13626 33017.14751 -244978.226

2974.19 0 896.1 0.448 0.28134 0.14067 31852.55787 -264079.2824

2855.542 0 912.1 0.456 0.29027 0.145135 30581.87836 -284586.6759

2726.619 0 928.1 0.464 0.29928 0.14964 29201.15712 -306486.4028

2584.602 0 944.1 0.472 0.30842 0.15421 27680.20361 -332812.5836


24/24


Appendix-4

Distribution of work:

Oscar Rosales Title page, list of units, and brought everyones work toget her

Christian Lugo Abstract and Theory

Michael Gooneratne - ResultsTodd Yeakley Procedure and Experimental Set up

Mina Alad Al Malak Discussion and conclusion

Tony Cardenas - Sample Calculation and Error Analysis

Documents

Experiment 1_Full Lab Report_Group A_v1.1