: Laboratory Materials Testing
Compute or estimate
the elastic modulus, yield strength (if applicable), ultimate strength,
maximum strain (AKA,
Percentage Elongation or Contraction), and toughness of engineering materials from experimental data.
between material failures such as the crushing of concrete in compression or the yielding/fracture of steel in
material failures such as occurs in buckling or local buckling of a long and slender compression member.
strengths of steel, aluminum, wood, and concrete.
the effect of length
Philpot Chapter 3.
You will perform the following tests.
rolled Grade 50 steel in tension
Aluminum 6061 specification, in tension
Concrete in tension
) in compression
Concrete in compression
different lengths of 1/8”x2”
steel flat in buckling (compression)
Test 3/8” diameter Grade 2 Steel Bolts in Shear
Test 3/8” diameter Grade 2 Steel Bolts in Tension
your raw notes from the lab:
dimensions, loads, readings
. Unlike other aspects of the assignment, presentation
does not count
for raw data
because it is understood that the data was taken in the lab.
and completeness are
important, but neatness will not count
Be sure to re
Title for the test, cross
sectional dimensions, units used, all loads, all deformations
All graphs must be made to scale, must give the units, and must provide a sufficient title that
adequately describes the test that was
performed so that it could be understandable by someone who did not witness the test.
brief written description of the test should also be included on the graphs.
Bar Graph #1. Make a bar graph (you may use Excel) that compares the
ultimate strengths o
f Grade 50 Steel
6061 Aluminum (tension), Douglas Fir (compression), and
(tension and compression)
Use units of ksi
Y Plot #1. Plot the stress
for Grade 50
and 6061 Aluminum
up to a strain of 0.010
strain on the x
axis and strain on the y
On the graph
, label the values for t
he following: Elastic Modulus and
Clearly show how the elastic moduli were determined by a
fit of the linear portion
of the curves.
Y Plot #2. Plo
t the stress
strain curve for Grade 50 Steel and 6061 Aluminum
for their full ranges
(including the period
during which the divider and ruler were used for measurement), placing strain on the x
axis and strain on the y
the graph, label the values
for the following: Elastic Modulus, Yield Stress, Ultimate Stress, % elongation, and the
refer to notes from lab for more information
). Note that toughness is simply the area under the stress
curve and can be found as the sum of trapez
oidal areas: show your work for this (hint: it is easy to use the data in Excel
to sum trapezoidal areas).
Y Plot #3
. Plot the stress
full range. On the graph, label the values for
, Ultimate Stress
(note: concrete and wood do not “yield”. Only metals yield).
both materials are non
linear, determine the elastic modulus as the slope of the line between the origin and a point
corresponding with 40% of the ultimate lo
Y Plot #4.
Plot Ultimate Stress (y
axis) versus Length
for the buckling specimens. Comment: at zero length,
would the plot approach the
previously determined yield strength of the material?
Compute the sh
ngth and tensile strength
of the Grade 2 Steel bolts and determine the ratio of shear strength/tensile
strength (note: this is a constant value for all ductile metals).
Provide written answers to the following:
How many times
stiffer is Steel, compared with Aluminum
(as measured by the elastic modulus)?
Which is more ductile, Steel or Aluminum?
Compare the stiffness (as measured by the elastic modulus) and strength of wood and concrete.
all intermediate calculations (example: the determinati
on of stresses and strains, based on the experimental loads