Compression Test of tubing

SRJC, ENGR 45, Fall 2013 Cameron Phillips, Andre Espinoza,

Simran Singh

Compression tests were done on three samples of 304 stainless steel tubing and three samples of copper tubing , each sample had a different diameter and wall thickness. The purpose of this experiment was to compare the stress strain curves of tubing with the tensile stress strain curves.

304 stainless steel A.K.A 18-8

• <0.08% Carbon • <2.0% Manganese • <0.75% Silicon • <0.045% Phosphorus • <0.030% Sulfur • 18.0%<Chromium<20.0% • 8.0%<Nickel<10.5% • <0.1% Nitrogen

copper

99.9% pure copper

304 stainless samples

• Each sample was cut to 6 inches in length • 1: 1.00” diameter, 0.083” wall thickness, cross

sectional area= 0.2391 square inches • 2: 0.75” diameter, 0.065” wall thickness, cross

sectional area= 0.1399 square inches • 3: 0.50” diameter, 0.049” wall thickness, cross

sectional area= 0.0694 square inches

Copper samples

• Each sample was cut to 6 inches in length • 1: 1.00” diameter, 0.050” wall thickness, cross

sectional area= 0.1492 square inches • 2: 0.625” diameter, 0.040” wall thickness,

cross sectional area= 0.0735 square inches • 3: 0.250” diameter, 0.030” wall thickness,

cross sectional area= 0.0207 square inches

304 stress strain curve

http://www.chegg.com/homework-help/questions-and-answers/using-stress-strain-data-given-figure-18-8stainless-steel-determine--yield-stressb-tensile-q694223

Copper stress strain curve

http://www.copper.org/resources/properties/144_8/

Graphs from our data

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1000

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4000

5000

6000

7000

0 0.05 0.1 0.15 0.2

stress

Strain

304 stainless steel

1 inchdiameter0.75 inchdiameter

0

1000

2000

3000

4000

5000

6000

7000

8000

0 0.01 0.02 0.03 0.04 0.05

stress

strain

Copper stress strain

1 Inch diameter

0.625 diameter

0.25 inch diameter

Modes of Deformation in Compression Testing

http://www.instron.us/wa/applications/test_types/compression.aspx?ref=http://www.google.com/url

The figure to the right illustrates the modes of deformation in compression testing. (a) Buckling, when L/D > 5. (b) Shearing, when L/D > 2.5. (c) Double barreling, when L/D > 2.0 and friction is present at the contact surfaces. (d) Barreling, when L/D < 2.0 and friction is present at the contact surfaces. (e) Homogenous compression, when L/D < 2.0 and no friction is present at the contact surfaces. (f) Compressive instability due to work-softening material1.