Comparative
Load Test
April 16, 2007
American Stainless Tubing,
Inc. (ASTI) submitted two lots of stainless steel
tubing for load/deflection testing. The first lot samples were 53 inches
long and the second lot samples were 57 inches long. All
of the tubing tested was 1.250” OD x .062” wall
thickness. Five of the samples are Type 304L
and six of the samples are Type 201HP Stainless Steel
to ASTM-554. All of the tubes were polished
to a 180 grit finish. All material was manufactured
by the same mill.
Load Test
Test No. 1 Mid-Point
Load Test
The 53 inch long tubes were
subjected to a center point load of 330 lbs. These tests were performed
in an Instron Testing Machine, Model 4206 (Electro
Mechanical System). The base of the machine
was extended using an I-beam. Figure
1-1 shows
the machine set-up prior to testing. The load
was applied through a plastic block with a special
ID configuration to prevent surface indentation. The
ends of each tube were firmly clamped in place on
the I-beam. Figure
1-2 shows the test set-up
prior to applying the load. Each tube was held
under load for a period of 10 minutes and the permanent
deflection was measured after load removal. Figure
1-3 shows the tube under load. The deflection-under-load
readings were directly recorded by the computer. The
results of this test are summarized in Table 1.
Test
No. 2 Uniform
Load Test
The 57 inch long tubes were
subjected to a distributed load test of 60 lbs.
every six inches, beginning at 4-1/2 inches from
one end for a total of nine locations. Figure
2-1 shows the set-up prior
to testing. Each tube was held under a total
load of 540 lbs for a period of 10 minute. The
initial deflection was recorded using a dial indicator
after the 10 minute period. Figure
2-2 shows
the tube during the load test. The permanent
deflection was recorded using a dial indicator after
the load was removed. Figure
2-3 shows the
permanent deflection of the tube.
The load test was
conducted at the University of Pennsylvania by Dr.
Alex Radin. Dr.
Radin is the director of the Mechanical Testing
Center.
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Figure 1-1
Figure 1-2
Figure 1-3
Figure 2-1
Figure 2-2
Figure 2-3
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