City College of New York

CE 332

Mechanics of Materials

Professor Ghosn





















Lab # 1

Bars under Uniaxial Loading





















Jason Rodriguez

I.D 5111

Due: March 9th, 2005



TABLE OF CONTENTS



Abstract__________________________________________ _____________________3

Introduction______________________________________ ______________________4

Procedure_________________________________________ _____________________5

Result & Analysis__________________________________________ _____________7

Conclusion________________________________________ ____________________ 21

References________________________________________ _____________________22

Appendix A_________________________________________________ ___________22

Appendix B_________________________________________________ ___________22





LIST OF ILLUSTRATIONS





FIGURES



Figure 1: Normal stress due to centric load___________________________________ 4

Figure 2: Electro Mechanical Testing Machine________________________________ 5

Figure 3: Gage Length before Elongation____________________________________ 6

Figure 4: Steel: Stress versus Strain_________________________________________ 9

Figure 5: Steel: Loading and Unloading in Linear Elastic Range __________________ 9

Figure 6: Steel: Yielding__________________________________________ ________10

Figure 7: Steel: Strain-Hardening_________________________________________ __10

Figure 8: Steel: Necking___________________________________________ _______11

Figure 9: Steel: Yielding, Ultimate and Rupture Strength________________________11

Figure 10: Aluminum: Stress versus strain___________________________________ 15

Figure 11: Aluminum: Linear Elastic Range__________________________________15

Figure 12: Aluminum: Loading and Unloading________________________________16

Figure 13: Aluminum: Strain-Hardening ____________________________________ 16

Figure 14: Aluminum: Necking___________________________________________ _ 17

Figure 15: Aluminum: Yielding, Ultimate and Rupture Strength__________________ 17

Figure 16: Steel: Modulus of Elasticity from Slope of Stress versus Strain 1_________19

Figure 17: Steel: Modulus of Elasticity from Slope of Stress versus Strain 2_________19

Figure 18: Aluminum: Modulus of Elasticity from Slope of Stress versus Strain 1____ 20

Figure 19: Aluminum: Modulus of Elasticity from Slope of Stress versus Strain 2____ 20



TABLES



Table 1: Portion of Raw Data for Steel_______________________________________7

Table 2: Summary of Steel findings_________________________________________1 2

Table 3: Portion of Raw Data for Aluminum__________________________________13

Table 4: Summary of Aluminum findings ____________________________________18





ABSTRACT





























































































INTRODUCTION



Material characteristics and properties of steel and aluminum are important when used in construction of buildings, bridges and various structures. Understanding how these materials react during applied loads is very important in construction and design. Characteristics that aid engineers in utilizing the right material for the specific tasks are yielding strengths, ultimate strength, and the rupture strength. These characteristics can be calculated from the data obtained from the engineering tension test.

The specimens used for the tensile test in this experiment are two bars each with a constant circular cross-sectional area, which is then put under an increasing axial load. The line of action of the load at both ends passes through the centroid of the bar. The load is then systematically applied at this centroid, where the loading is increased until the bar ruptures or fails. Since the loadings is at both ends of the bar and are directed away from the bar, this produces a tensile force acting longitudinally through the bar.

The centric loading produces normal stresses in the rod that acts perpendicular to its cross-section as seen in figure 1. From these normal stresses, and the strain in the bar one can accurately determine the yielding strength, ultimate strength, rupture strengths and the modulus of elasticity of the bar.





Figure 1: Normal stress due to centric load

PROCEDURE

An INSTRON 8500 PLUS Testing System was used for the tensile test. The bar is loaded into a machine where both ends of the specimen are held in position by powerful grips, see figure 2. These grips exert the simultaneous load at each end via an electronically driven gear (or hydraulics). The machine pulls at these grips in opposite direction, thus producing the tensile force. The load and strain are recorded for analysis.



Figure 2: Electro Mechanical Testing Machines

Two separate tests were performed in this experiment; the first test was steel, while the second test was aluminum. Each bar is comprised of the same cross-sectional area, and a given test length that is measured between two points, referred to as gage marks. The change in gage length is measured by mechanical extensometers, which are placed at the designated gage marks, see figure 3. As the load is applied at the ends of the bar, the bar begins to elongate. The elongation can be measured by the change between the gage marks compared to the original gage length. This strain caused by the elongation and the load at that specific time is recorded. The data obtained from the test is then saved onto a computer excel file, where the raw data may be used to calculate properties of the tested material.



Figure 3: Gage Length before Elongation

Using this information obtained from the INSTRON 8500, we can plot the relationship between stress and strain. Normal stress s is found by dividing the applied load P on the bar, by its cross-sectional area A0. (We can visually see that the area of the bar decreases as the load increases, we use the engineering stress, in which the original cross sectional area A0 is used). The elongation data provided by the extensometer one can calculate the strain e. The strain can be calculated by taking the change in elongation, L-Lo, divided by the original length Lo. Plotting a diagram of stress versus strain we can find the modulus of elasticity from the slope s versus e in its linear elastic stage (Linear portion of the graph) . Yield, ultimate and rupture strength is also obtained from the rest of the stress versus strain diagram.

RESULT & ANALYSIS

Using the raw data, a table was constructed; see Table 1, & Table 2, where the stress and strain were calculated from the data points obtained from the engineering tension test. Multiple diagrams were constructed to visually display the data and its defining characteristics.

Table 1: Portion of Raw Data for Steel

Steel Bar Diameter = 0.335 in^2

Area = 0.0881

Gage Length = 2"



Load (Kip) Load (lbs) Stress (psi) Elongation (in) Strain(in/in)

1 0.1673 167.2948 1898.0292 0.0040 0.0020

2 0.1610 160.9634 1826.1975 0.0040 0.0020

3 0.1671 167.1139 1895.9769 0.0040 0.0020

4 0.1729 172.8623 1961.1955 0.0039 0.0019

5 0.4305 430.4976 4884.1757 0.0042 0.0021

6 0.5367 536.6833 6088.8960 0.0042 0.0021

7 0.7678 767.7671 8710.6392 0.0045 0.0022

8 1.1434 1143.3865 12972.1979 0.0046 0.0023

9 1.3101 1310.0649 14863.2340 0.0048 0.0024

10 1.4479 1447.9273 16427.3406 0.0049 0.0024

11 1.5932 1593.1662 18075.1366 0.0050 0.0025

12 1.7676 1767.5628 20053.7390 0.0051 0.0026

13 1.9758 1975.7601 22415.8244 0.0052 0.0026

14 2.1438 2143.8186 24322.5183 0.0054 0.0027

15 2.2863 2286.2972 25938.9976 0.0055 0.0028

16 2.3861 2386.0644 27070.8982 0.0055 0.0028

17 2.4811 2481.0546 28148.6017 0.0056 0.0028

18 2.5963 2596.3453 29456.6229 0.0058 0.0029

19 2.7342 2734.1608 31020.1974 0.0059 0.0029

20 2.9202 2920.1951 33130.8343 0.0059 0.0030

21 3.0671 3067.1491 34798.0889 0.0061 0.0030

22 3.0690 3068.9715 34818.7648 0.0061 0.0031

23 3.0683 3068.2814 34810.9353 0.0060 0.0030

24 3.0677 3067.7186 34804.5501 0.0060 0.0030

25 3.1732 3173.2410 36001.7458 0.0063 0.0031

26 3.1815 3181.4684 36095.0891 0.0061 0.0031

27 3.1860 3185.9773 36146.2445 0.0061 0.0030

28 3.0697 3069.6817 34826.8223 0.0060 0.0030

29 2.8576 2857.5985 32420.6497 0.0058 0.0029

30 2.6425 2642.4871 29980.1209 0.0058 0.0029

31 2.4531 2453.1163 27831.6300 0.0056 0.0028

32 2.3246 2324.6404 26374.0172 0.0055 0.0027

33 2.2557 2255.6991 25591.8494 0.0055 0.0027

34 2.1672 2167.1809 24587.5734 0.0054 0.0027

35 2.0902 2090.1865 23714.0397 0.0053 0.0027

36 2.0044 2004.3683 22740.3964 0.0053 0.0026

37 1.9176 1917.6256 21756.2642 0.0053 0.0026

38 1.7935 1793.5314 20348.3636 0.0052 0.0026

39 1.6810 1681.0010 19071.6591 0.0050 0.0025

40 1.5785 1578.5204 17908.9739 0.0050 0.0025

41 1.5109 1510.8789 17141.5528 0.0048 0.0024

42 1.4326 1432.5981 16253.4244 0.0048 0.0024

43 1.2448 1244.8487 14123.3290 0.0047 0.0024

44 1.1072 1107.2007 12561.6548 0.0046 0.0023

45 0.9914 991.4075 11247.9326 0.0045 0.0023

46 0.9433 943.2960 10702.0876 0.0045 0.0022

47 0.8523 852.3257 9669.9914 0.0044 0.0022

48 0.7257 725.6788 8233.1294 0.0042 0.0021

49 0.5898 589.8330 6691.9022 0.0042 0.0021

50 0.4814 481.4030 5461.7178 0.0042 0.0021

51 0.4485 448.4599 5087.9649 0.0042 0.0021

52 0.4384 438.4302 4974.1744 0.0040 0.0020

53 0.4306 430.6450 4885.8480 0.0041 0.0021

54 0.4322 432.1525 4902.9508 0.0041 0.0021

55 0.4318 431.7639 4898.5421 0.0041 0.0021

56 0.4133 413.2657 4688.6719 0.0041 0.0020

57 0.4139 413.8955 4695.8170 0.0041 0.0020

58 0.4255 425.5264 4827.7746 0.0040 0.0020

59 0.7692 769.2478 8727.4379 0.0043 0.0022

60 1.0934 1093.3655 12404.6887 0.0046 0.0023

61 1.2681 1268.1038 14387.1678 0.0047 0.0024

62 1.4474 1447.3578 16420.8794 0.0048 0.0024

63 1.6326 1632.5679 18522.1654 0.0049 0.0024

64 1.8071 1807.1186 20502.5160 0.0050 0.0025

65 2.0051 2005.0517 22748.1498 0.0053 0.0027

66 2.1742 2174.1555 24666.7031 0.0054 0.0027

67 2.3411 2341.0818 26560.5518 0.0055 0.0027

68 2.5291 2529.0991 28693.6867 0.0056 0.0028

69 2.6928 2692.7559 30550.4415 0.0056 0.0028

70 2.8557 2855.7494 32399.6709 0.0058 0.0029

71 3.0338 3033.7706 34419.3958 0.0060 0.0030

72 3.2178 3217.8417 36507.7594 0.0061 0.0031

73 3.3809 3380.8553 38357.2169 0.0062 0.0031

74 3.5594 3559.4058 40382.9469 0.0064 0.0032

75 3.7160 3715.9742 42159.2809 0.0065 0.0033



Figure 4: Steel: Stress versus Strain

Figure 5: Steel: Loading and Unloading in Linear Elastic Range

Figure 6: Steel: Yielding

Figure 7: Steel: Strain-Hardening

Figure 8: Steel: Necking

Figure 9: Steel: Yielding, Ultimate and Rupture Strength



Table 2: Summary of Steel findings

Steel Bar Diameter = 0.335 in^2

Area = 0.0881

Gage Length = 2"

Loading Unloading Load till Rupture



Load (Kip) Load (lbs) Stress (psi) Elongation (in) Strain(in/in)

1 0.1673 167.2948 1898.0292 0.0040 0.0020

27 3.1860 3185.9773 36146.2445 0.0061 0.0030

28 3.0697 3069.6817 34826.8223 0.0060 0.0030

58 0.4255 425.5264 4827.7746 0.0040 0.0020

59 0.7692 769.2478 8727.4379 0.0043 0.0022

87 5.5230 5522.9521 62660.2006 0.0078 0.0039

88 4.8327 4832.6752 54828.7206 0.0070 0.0035

89 4.8398 4839.8038 54909.5976 0.0071 0.0035

90 4.8546 4854.6038 55077.5097 0.0071 0.0035

111 4.9625 4962.4576 56301.1562 0.0071 0.0036

112 4.9154 4915.4449 55767.7775 0.0071 0.0035

182 0.3908 390.8011 4433.8023 0.0058 0.0029

183 0.6401 640.0751 7261.9192 0.0062 0.0031

221 4.4581 4458.0743 50578.7168 0.0090 0.0045

222 4.2869 4286.8668 48636.2961 0.0087 0.0044

271 0.4308 430.8125 4887.7483 0.0059 0.0029

272 2.5991 2599.1124 29488.0168 0.0075 0.0037

379 6.7051 6705.0837 76071.9779 0.3680 0.1840

380 6.6974 6697.3588 75984.3357 0.3746 0.1873

411 4.8176 4817.6341 54658.0730 0.5293 0.2646





1. Yielding Strength: 63,600 psi (Line item # 87)

2. Ultimate Strength: 76,072 psi (Line item # 379)

3. Rupture Strength: 54,658 psi (Line item # 411)









Table 3: Portion of Raw Data for Aluminum

Aluminum Bar Diameter = 0.335 in^2

Area = 0.0881

Gage Length = 2"



Load (kip) Load (lbs) Stress (psi) Strain (in) Strain (in/in)

1 0.0852 85.2286 966.9535 0.0097 0.0048

2 0.0824 82.3811 934.6483 0.0095 0.0048

3 0.0914 91.3991 1036.9609 0.0096 0.0048

4 0.0890 88.9872 1009.5965 0.0095 0.0047

5 0.1623 162.3101 1841.4761 0.0097 0.0049

6 0.3467 346.6560 3932.9568 0.0101 0.0051

7 0.5827 582.7044 6611.0250 0.0106 0.0053

8 0.8302 830.2230 9419.2266 0.0111 0.0056

9 1.0634 1063.3905 12064.6098 0.0116 0.0058

10 1.4155 1415.5336 16059.8205 0.0124 0.0062

11 1.5601 1560.1361 17700.3963 0.0126 0.0063

12 1.6886 1688.6254 19158.1612 0.0130 0.0065

13 1.8066 1806.6295 20496.9670 0.0132 0.0066

14 1.9352 1935.2261 21955.9492 0.0134 0.0067

15 2.0820 2082.0328 23621.5326 0.0137 0.0069

16 2.2032 2203.2461 24996.7481 0.0141 0.0071

17 2.3763 2376.3028 26960.1488 0.0144 0.0072

18 2.5707 2570.7453 29166.1802 0.0148 0.0074

19 2.7756 2775.5792 31490.1065 0.0153 0.0077

20 2.9708 2970.8324 33705.3356 0.0156 0.0078

21 2.9963 2996.3185 33994.4861 0.0158 0.0079

22 3.0625 3062.5464 34745.8693 0.0160 0.0080

23 3.0639 3063.8729 34760.9190 0.0159 0.0079

24 3.0696 3069.6214 34826.1381 0.0159 0.0079

25 3.0681 3068.0804 34808.6549 0.0159 0.0079

26 3.0668 3066.8008 34794.1373 0.0160 0.0080

27 3.1966 3196.5765 36266.4968 0.0163 0.0082

28 3.1974 3197.4274 36276.1506 0.0162 0.0081

29 3.2008 3200.8242 36314.6888 0.0162 0.0081

30 3.1190 3118.9656 35385.9687 0.0160 0.0080

31 2.9423 2942.3179 33381.8267 0.0157 0.0078

32 2.8209 2820.8902 32004.1787 0.0153 0.0077

33 2.5876 2587.5886 29357.2745 0.0148 0.0074

34 2.3675 2367.4523 26859.7361 0.0144 0.0072

35 2.1974 2197.4441 24930.9220 0.0141 0.0070

36 2.1073 2107.3381 23908.6318 0.0138 0.0069

37 2.0239 2023.9185 22962.2016 0.0136 0.0068

38 1.9680 1967.9548 22327.2700 0.0136 0.0068

39 1.9263 1926.2885 21854.5484 0.0133 0.0066

40 1.8779 1877.8956 21305.5107 0.0134 0.0067

41 1.8113 1811.2792 20549.7198 0.0131 0.0066

42 1.7294 1729.3738 19620.4688 0.0129 0.0064

43 1.6098 1609.7885 18263.7236 0.0127 0.0064

44 1.4754 1475.4301 16739.3713 0.0125 0.0062

45 1.3468 1346.8335 15280.3891 0.0122 0.0061

46 1.2189 1218.8601 13828.4774 0.0119 0.0059

47 1.1027 1102.7319 12510.9544 0.0117 0.0059

48 0.9988 998.8309 11332.1543 0.0115 0.0058

49 0.8985 898.5143 10194.0208 0.0113 0.0056

50 0.8122 812.1937 9214.6773 0.0110 0.0055

51 0.7331 733.1156 8317.5031 0.0110 0.0055

52 0.6456 645.5823 7324.4013 0.0107 0.0054

53 0.5552 555.2351 6299.3743 0.0106 0.0053

54 0.4564 456.3657 5177.6596 0.0103 0.0052

55 0.4373 437.2511 4960.7962 0.0101 0.0051

56 0.4371 437.1439 4959.5801 0.0102 0.0051

57 0.4307 430.7120 4886.6082 0.0102 0.0051

58 0.4336 433.5729 4919.0655 0.0102 0.0051

59 0.4341 434.1223 4925.2984 0.0103 0.0052

60 0.4242 424.2065 4812.8001 0.0101 0.0051

61 0.4182 418.2102 4744.7690 0.0102 0.0051

62 0.4213 421.2586 4779.3547 0.0103 0.0051

63 0.5644 564.4072 6403.4353 0.0104 0.0052

64 0.7071 707.1203 8022.5751 0.0108 0.0054

65 0.7982 798.2447 9056.4195 0.0110 0.0055

66 0.8795 879.5404 9978.7538 0.0112 0.0056

67 0.9596 959.5967 10887.0258 0.0113 0.0056

68 1.0393 1039.2510 11790.7371 0.0115 0.0057

69 1.1154 1115.4415 12655.1502 0.0117 0.0058

70 1.1982 1198.2246 13594.3590 0.0118 0.0059

71 1.2761 1276.1369 14478.3067 0.0121 0.0060

72 1.3547 1354.6723 15369.3236 0.0121 0.0061

73 1.4332 1433.1542 16259.7336 0.0123 0.0061

74 1.5104 1510.3898 17136.0038 0.0124 0.0062

75 1.5877 1587.6724 18012.8072 0.0127 0.0063



Figure 10: Aluminum: Stress versus strain

Figure 11: Aluminum: Linear Elastic Range

Figure 12: Aluminum: Loading and Unloading

Figure 13: Aluminum: Strain-Hardening

Figure 14: Aluminum: Necking

Figure 15: Aluminum: Yield, Ultimate and Rupture Strength

Table 4: Summary of Aluminum Findings

Aluminum Bar 0.335 in^2

Area = 0.0881

Gage Length = 2"

Loading Unloading Load till Rupture

Load (kip) Load (lbs) Stress (psi) Strain (in) Strain (in/in)

1 0.0852 85.2286 966.9535 0.0097 0.0048

29 3.2008 3200.8242 36314.6888 0.0162 0.0081

30 3.1190 3118.9656 35385.9687 0.0160 0.0080

57 0.4307 430.7120 4886.6082 0.0102 0.0051

58 0.4336 433.5729 4919.0655 0.0102 0.0051

157 4.4173 4417.2589 50115.6490 0.0312 0.0156

158 4.4041 4404.0803 49966.1323 0.0313 0.0156

208 0.3767 376.7248 4274.1004 0.0224 0.0112

209 0.4528 452.8081 5137.2970 0.0227 0.0114

266 4.6565 4656.5166 52830.1276 0.0704 0.0352

267 4.3913 4391.2770 49820.8735 0.0698 0.0349

310 0.4308 430.8259 4887.9003 0.0604 0.0302

311 1.3603 1360.2667 15432.7944 0.0625 0.0313

317 4.9908 4990.7778 56622.4607 0.0719 0.0360

*317.5 OFF SET METHOD 2% 56629.7201 0.0364

318 4.9921 4992.0575 56636.9794 0.0734 0.0367

409 5.8405 5840.5442 66263.4158 0.3603 0.1802

410 5.8321 5832.0890 66167.4880 0.3649 0.1825

422 5.0077 5007.6681 56814.0882 0.4512 0.2256

423 4.8861 4886.1399 55435.3000 0.4568 0.2284





1. Yielding Strength: 56,630 psi (Line item # 317.5)

2. Ultimate Strength: 66,623 psi (Line item # 409)

3. Rupture Strength: 55,435 psi (Line item # 423)











Figure 16: Steel: Modulus of Elasticity from Slope of Stress versus Strain 1

Figure 17: Steel: Modulus of Elasticity from Slope of Stress versus Strain 2

Figure 18: Aluminum: Modulus of Elasticity from Slope of Stress versus Strain 1

Figure 19: Aluminum: Modulus of Elasticity from Slope of Stress versus Strain 2

Using the data plotted for the stress strain diagrams for steel and aluminum, we can calculate the modulus of elasticity (E) for each of the tested materials. The modulus is the slope of the trend line for the material in the linear elastic range.

As you can see in figures 16 and 17, which were taken for two different loadings, both in the linear elastic range, and both yield the same modulus of elasticity. I choose to test the slope at two different loading points to double check that the modulus of elasticity is the same. The modulus of elasticity for the tested materials is listed below.

E (Steel) = 3*10^7 Pa or 30Mpa

E (Aluminum)= 1*10^7 or 10Mpa

CONCLUSION

Steel and aluminum are both classified as ductile materials due to the fact that the stress versus strain diagrams shares many similarities such as containing yielding point, stress hardening, necking and rupture. The biggest similarity between them is that ductile materials yield at normal temperature.

Before a material reaches its yielding point, the relationship between it load and length increase linearly. Once the yielding point is reached, in all ductile materials, the specimen lengths changes at a larger rate for a small increase in the applied load. This is where we begin the signs of shear stress, which led to the large elongation, and will ultimately lead to rupture of the material after a maximum load of the material has been reached, we can visually see a large decrease in diameter, where the loads are needed to make the material fail. The main cause for rupture is due to shearing stresses in the bar. The shearing stresses are the greatest at an angle of 45 degrees, which can be visually seen in the specimen.

References

Beer, Johnston, DeWolf. Mechanics of Materials: Third Edition. McGraw-Hill 2002



Appendix A: Key Terms and Formulas Used In Calculations



Ultimate Strength: The stress corresponding to the maximum load reached in the tensile test.

Proportional Limit: The stress at which the strain ceases to be proportional to the stress (the limit of the straight part of the stress vs. strain diagram). This quantity indicates the range of stress in which the assumption of elastic action is valid.

Yield Strength: The stress determined by some arbitrary permanent strain. The most commonly used yield stress is the one determined by a line passing through a strain of 0.002, parallel with the elastic line. The yield stress represents a practical upper limit for the actual stress developed in a structure.

Ductility: The total normal strain that has occurred at failure (usually measured as the total permanent strain after failure). Elongation is generally specified in percent and is regarded as a measure of the ductility of a material.

Modulus of Elasticity: The ratio of stress to strain within the linear elastic range of a material. (The slope of the linear relationship between the stress vs. strain diagram)

Appendix B: Formulas used in calculations

Cross-sectional area of cylindrical rod = p (d2/4); where (d=diameter)

Stress = Force / Original Cross-sectional Area à s = P / A0

Strain = Deformation / Original Length à e = L-L0/ L0

Modulus of Elasticity, E = Stress/Strain à E = s/e

 

Okay, did you type all of that? Because that would have been impressive.

 

and... why?

 

yes that is mines but um.. dunno how to upload an excel file so your missing all the kewl graphs i made. Just cuase im ghetto doesnt mean im dumb lol



Or does it YO

 

Thats nto **** homie, one time I tagged that **** on a fuckinb building, took 20 cans of ****** paint *****...



Westsiiiide!!

 

hmm jew so funny dude.

Thats a report for my Mechanics of Materials classs. This weeks lab is Torsion and Pure Bending moment

 

Here's a tip. I don'tk now how your school works, but at my school and at my work... all the raw data is shoved into the appendix. Only graphs and final calculated results (with a very very small amount of raw data is presented). You are better off defining the equations and labeling them equation 1.0, 1.2, 2.1 etc and then sticking the graph after it and referencing the raw data in teh appendix.

 

Wow Cheers, you're almost...ALLLLLmost U Waterloo material



You are right though. Stick raw data in the appendix.



Also, I found that it was helpful to leave printing and binding until 1 hour before the report was due. And try to be hung over (or better yet, still drunk) while you are trying to print, assemble different files, and do the self-binding ('cause it's cheaper). The dash to the dropbox is good exercise, as is knocking over the TA as he tries to open the box and collect the reports.

 

yeah i was thinking bout putting in the back but i decided to leave it there =) ,l I know how to write them just dont agree with all of them and plus is didn have massive equations they were simple enuff and used in the text lloll



anyone here good with fluid mechanics..



Please explain surface tension to me, i thought i had it down pat but i guess i was wrong. i remeber someone saying they were good in fluids dunno who it is



Jason NYC

 

If someone on this forum is "good in fluids", I suspect he meant that he could shoot a really impressive stream of **** after drinking a six-pack.