Activity 2.3.2 Tensile Testing – SSA
Introduction
Tensile testing provides engineers with the ability to verify and establish material
properties related to a specific material. This verification process is critical in insures
the selected material will meet design specifications. In this activity you will interpret
and make sample specific calculations related to the material properties of a dog
bone test sample.
Equipment
Dog bone test sample
SSA 1000 Tensile Tester
Computer with SSA 1000 Software
Dial Caliper
Permanent Marker
Material Testing Formula Sheet
Procedure
1. Identify test sample material type
:______________________________
2. Using a dial caliper measure and
record five diameter
measurements of the narrowed
dog bone testing region.
a. __________
b. __________
c. __________
d. __________
e. __________
3. Identify and rerecord the smallest :______________________________
measurement from the dog bone
testing region.
4. Using a permanent marker place
two indexing dots on the dog
bone testing region. (Dots should
be positioned at the ends of the
region)
5. Using a dial caliper measure and
:______________________________
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POE Activity 2.3.2 Tensile Testing SSA – Page 1
record the distance between the
two indexing dots.
6. Position the test sample in the tensile tester as directed by your teacher.
7. Tensile test your test sample as directed by your teacher.
8. Position your broken dog bone
broken end to end.
9. Using a dial caliper measure and
record the distance between the
two indexing dots.
:______________________________
10. Using a dial caliper measure the
diameter of the necking region of
the dog bone test sample
:______________________________
11. Calculate the test samples total Strain/Deformation – The total amount of
elongation of a sample to rupture normalized (divided) by the initial length.


total
= total/L0
total
=
12. Calculate the test samples ductility- The ability of a material to be deformed
plastically without rupture.
% of Elongation
= total (100)
% of Elongation =
13. Calculate the test samples reduction in area
Reduction in area = (A original – A final)/A original*100
Reduction in area =
14. Create a print screen of your completed tensile test and insert the graph into the
test sample calculations tables.
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POE Activity 2.3.2 Tensile Testing SSA – Page 2
Test sample calculations
Proportional Limit Stress
The greatest stress that a material is capable of withstanding without deviation from
straight line proportionality between the stress and strain. If the force applied to a
material is released, the material will return to its original size and shape.
Tensile test results graph (Insert test graph)
Locate the proportional limit on the test graph.
Solve for the proportional limit stress:  = F/A
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POE Activity 2.3.2 Tensile Testing SSA – Page 3
Yield Point Stress
The point at which a sudden elongation takes place, while the load on the sample
remains the same or actually drops. If the force applied to the material is released,
the material will not return to its original shape.
Tensile test results graph (Insert test graph)
Locate the Yield Point on the test graph.
Solve for the Yield Point stress:  = F/A
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POE Activity 2.3.2 Tensile Testing SSA – Page 4
Ultimate/Tensile Stress
The point at which a maximum load for a sample is achieved. Beyond this point
elongation of the sample continues, but the force exerted decreases.
Tensile test results graph (Insert test graph)
Locate the maximum load location on the test graph.
Solve for the Ultimate/Tensile stress:  = F/A
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POE Activity 2.3.2 Tensile Testing SSA – Page 5
Breaking/Rupture Point
The maximum amount of stress that can be applied before rupture occurs. The
specimen fractures in the necking region where the material reduces in diameter as
it elongates.
Tensile test results graph (Insert test graph)
Locate the Breaking/Rupture Point on the test graph.
Solve for the Breaking/Rupture Point stress:  = F/A
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POE Activity 2.3.2 Tensile Testing SSA – Page 6
Modulus of Elasticity
A measure of a material’s ability to regain its original dimensions after the removal of
a load or force. The modulus is the slope of the straight line portion of the stressstrain diagram up to the proportional limit.
Tensile test results graph (Insert test graph)
Solve for the Modulus of Elasticity: E =
(F2 -F1)L0
(δ2 -δ1)A
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Modulus of Resilience
A measure of a material’s ability to absorb energy up to the elastic limit. This
modulus is represented by the area under the stress vs. strain curve from 0-force to
the elastic limit.
Tensile test results graph (Insert test graph)
Solve for the Modulus of Resilience: Ur = ½(yp yp)
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POE Activity 2.3.2 Tensile Testing SSA – Page 8
Modulus of Toughness
A measure of a material’s ability to plastically deform without fracturing. Work is
performed by the material absorbing energy from the blow or deformation. This
measurement is equal to the area under the stress vs. strain curve from its origin
through the rupture point
Tensile test results graph (Insert test graph)
Solve for the Modulus of Toughness: Ut = 1/3 (br)( yp + 2 ult)
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POE Activity 2.3.2 Tensile Testing SSA – Page 9