Dr. Mark E. Barkey
Professor of  Aerospace Engineering and Mechanics
The University of Alabama 
Structural Durability and Fatigue Performance Group

Pressure Testing of Recyclable Transmission Lines (RTL's)

Toledo Metal Spinning Cone 2005 Results


T01-2005 cone
 
The 2005 project was focused on determining the affect of structural stiffening on the initial buckling
pressure of the cones.  Toledo Metal Spinning produced the cones as in the 2004 study, but this time
the cones were manufactured with a closed end by welding a cap on the end of the cone.

Instrumentation upgrades for this round of tests include the use of an electric winch instead of a hand
winch, and the use of a computer controlled, relay switched air pressure valve.

Due to a programming error in the data acquistion software related to the implementation of the computer
controlled pressure valve, the initial and ulitmate buckling pressures were not captured by the data
acqusition system.  This error was corrected for subsequent tests.  Fortunately, as a redundant data
acquisition technique, a video of one of the digital pressure gages was made during the test.

A frame grab of the video and the max value function of the digital pressure gage showed that the
initial and ultimate buckling pressure was 1.25 psi.

The T01-2005 cone was not stiffened, as the purpose of this test was to ensure that similar test
results would be obtained for these cones as for the previously tested cones.  The laser range finder
was used on this test to obtain pre-test scans and also for mode shape deterimination.

Strain gage rosettes were placed 25 inches into the cone (along the cone wall).
 
 




T01-2005 cone instrumented with strain gages.


T

T01-2005 cone, side view.
 
 

T01-2005 interior, post-buckling.
 
 

T01-2005 cone exterior, post-buckling.
 
 
 

T01-2005 initial (and ultimate) buckling pressure from gage.