PASCO AP-8214A User Manual
®
Instruction Manual
A
B
C
D
E
F
F
Stress-Str ain
platform
Lever arm
Coupon
clamps
Plunger
Pivot
Force Sensor
post
Belt
Crank
Fig. 1: Included Equipment
Lever arm
stop
Fig. 2: AP-8222 Plastic Test Coupons
*012-13282*
Stress/Strain Apparatus
AP-8214A
012-13282A
Included Equipment
A. AP-8221 Stress/Strain Apparatus without Coupons
B. Thumbscrews for Rotary Motion Sensor, 2 pieces
C. Attachment for force sensor
D. Replacement hex nut, 2 pieces
E. Calibration bar
F. Tee handle plus Socket, 3/8 inch
• PASCO Experiment Setup CD-ROM and Storage Box (not shown)
AP-8222 Plastic Test Coupons: 4 color-coded samples, 10 pieces per sample
• high impact polystyrene (HIPS)
• nylon 6 (15% glass fiber reinforced)
• acrylonitrile butadiene styrene (ABS)
• polypropylene (PP)
• The plastic coupons are attached to a rectangular plas-
tic rail called a ‘sprue’. Use scissors or a knife to cut the
coupon from the sprue.
800-772-8700 www.pasco.com
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Stress/Strain Apparatus 012-13282A Introduction
Fig. 3: AP-8223 Metal Test Coupons
AP-8223 Metal Test Coupons: 5 samples, 10 pieces
per sample (sample containers labeled with
thickness in inches)
• cold-rolled steel 0.003”
• annealed steel 0.003”
• aluminum 0.003”
• brass (thick) 0.005”
• brass (thin) 0.003”
Note: The metal coupons are packaged in plastic containers to prevent bending or creasing of the coupons.
Additional Equipment Required for Use with
ScienceWorkshop
Sensors Part Number
ScienceWorkshop Interface See PASCO catalog or www.pasco.com
DataStudio
1
See PASCO catalog or www.pasco.com
Economy Force Sensor CI-6746
Rotary Motion Sensor CI-6538
Additional Equipment Required for Use with
PASPORT Sensors Part Number
PASPORT Interface
DataStudio
1
2
See PASCO catalog or www.pasco.com
See PASCO catalog or www.pasco.com
Force Sensor PS-2104
Rotary Motion Sensor PS-2120
1
DataStudio 1.8 or later recommended. Visit www.pasco.com to download the latest version. DataStudio Lite, the free version, is
sufficient for use with the experiment set-up files on the included CD.
2
The two sensors used on the Apparatus require a single multi-port interface such as the Xplorer GLX (PS-2002) or PowerLink
(PS-2001), or two single-port interfaces such as the USB Link (PS-2100) or Xplorer (PS-2000).
Recommended Equipment Part Number
Replacement Test Coupons* AP-8217A
Digital Calipers SE-8710
*The AP-8217A Replacement Test Coupons include all of the AP-8222 plastic and AP-8223 metal test coupons.
Introduction
The PASCO AP-8214A Stress/Strain Apparatus illustrates the relationship between stress and strain for various materials. The apparatus stretches a test coupon (and breaks it in some cases) while measuring the amount of stretch and
force experienced by the test coupon. Data acquisition software can be used to generate a plot of force versus displacement and also a plot of stress versus strain.
The Stress/Strain Apparatus requires a ScienceWorkshop or PASPORT interface, DataStudio software, a Rotary
Motion Sensor (RMS), and a Force S ens or. Incl uded with th e appar atu s ar e four types of metal test coupons an d fo ur
types of plastic test coupons. Also included are a tee handle with a socket that fits the hex nuts on the coupon clamps,
a bar for calibrating the apparatus, and spare hex nuts for the coupon clamps.
This manual includes instructions for setting up the Stress/Strain Apparatus with ScienceWorkshop or P ASPORT sen-
sors. It also describes how to do the calibration and the data collection using the DataStudio set-up files that are on the
included PASCO Experiment Setup CD-ROM. The CD-ROM has a folder labeled “AP-8214 SETUP” that contains
two DataStudio configuration (set-up) files, two DataStudio workbook files, and a sample data file.
2
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Model No. AP-8214A 012-13282A Introduction
Fig. 4: Stress-Strain curve
Test Coupon Specifications
The data below are intended as a general guide only and do not necessarily represent results that may be obtained.
The units for tensile strength and modulus of elasticity are megapascals (MPa or 10
6
N/m2) and pounds per square
inch (psi).
AP-8222 Plastic Test Coupons
Item HIPS nylon 6 (+ 15% glass) ABS polypropylene
Color code orange black blue white
Cross-sectional area 2.482 mm
Tensile strength 23 MPa/
3410 psi
Tensile elongation 40% 2.5% 20% 9%
Modulus of elasticity 2000 MPa/
280000 psi
2
2.482 mm
98 MPa/
14000 psi
2900 MPa/
420000 psi
2
2.482 mm
47 MPa/
6800 psi
2300 MPa/
380000 psi
2
2.482 mm
34 MPa/
4900 psi
1900 MPa/
239000 psi
2
AP-8223 Metal Test Coupons
Item cold-rolled steel annealed steel aluminum brass (thin) brass (thick)
Cross-sectional area 0.303 mm
Tensile strength 620 MPa/
90,000 psi
2
0.303 mm
300 MPa/
44,000 psi
2
0.303 mm
145 MPa/
21,000 psi
2
0.303 mm
430 MPa/
44,000 psi
2
0.506 mm
430 MPa/
44,000 psi
2
Tensile elongation none 42-45% 6% 25% 25%
Modulus of elasticity 200,000 MPa/
29,000,000 psi
200,000 MPa/
29,000,000 psi
69,000 MPa/
10,000,000 psi
117,000 MPa/
17,000,000 psi
Theory.
A stress-strain tensile test measures the amount of stretching force
applied to a sample of material, and the amount of stretch of a material. Stress (σ) is the ratio of force (F) per unit of cross-sectional area
(A). Strain (ε) is the ratio of the change of length (l) compared to the
original length (L). A stress-strain curve is a graphical representation
of the load applied and the deformation of the sample. The curve varies from material to material.
Ductile materials like metal have a linear stress-strain relationship up
to a point. The slope of the linear part of the stress-strain curve is
called “Young’s modulus” or the modulus of elasticity (E) and is a
property used to characterize materials.
117,000 MPa/
17,000,000 psi
3
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Stress/Strain Apparatus 012-13282A Equipment Set-up
Fig. 5: Force calculation
ScienceWorkshop
PASPORT
Fig. 6: Three-step
pulley on the
“clockwise positive”
side of RMS
About the Apparatus
The lever arm on the Stress/Strain Apparatus is a Class III lever that
transmits the applied force to the Force Sensor. The length of the
lever arm from the pivot to the Force Sensor attachment is five times
longer than the length of the lever arm from the pivot to the coupon
clamp that is part of the lever arm. The force applied to the test coupon is five times more than the force measured by the Force Sensor.
Therefore, each DataStudio set-up file uses a calculation that multiplies the measured force by five.
Equipment Set-up
1. Attach the Rotary Motion Sensor to the apparatus platform.
• Remove the rod clamp from the RMS.
• Place the three-step pulley (Item 6) onto the shaft of the RMS with the largest pulley on the outside. The three-step pulley should be on the “clockwise positive” side
of the RMS as shown in the figure.
• Place the RMS on the platform as illustrated below. Use the two thumbscrews to
fasten the RMS to the platform from beneath.
• Seat the belt (Item 7)on the middle step of the three-step pulley and the groove on
the crankshaft.
2. Attach the Force Sensor to the apparatus platform.
• Remove the hook from the Force Sensor and replace it with the force sensor
attachment (Item 3, included).
• Place the Force Sensor on the apparatus platform by putting the support rod
mounting hole onto the Force Sensor post.
• Insert the long thumbscrew supplied with the Force Sensor through the hole on the
Force Sensor marked “Cart” and screw it into the threaded hole in the apparatus
platform.
• Tighten the setscrew (Item 4) in the support rod mount of the Force Sensor.
3. Clamp down the apparatus (optional). Use a large C-clamp to clamp the Appa-
ratus Platform to the edge of your bench or table. One side of the platform has
three feet. In order to avoid bending the platform, position the clamp directly over
the center foot.
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