Thursday, March 10, 2011

Salute to Discovery

This is my salute to Discovery, with a vintage 1960's Astronaut Snoopy and my mission cup from Discovery's STS-51 in the foreground, and one of the big test stands out my office window in the background. Snoopy is somewhat worse for wear, because he was a gift from my father, and my brother and I enjoyed him as kids.

Wednesday, March 09, 2011

FEA of Stringer Test Fixture

Here are some clips from a stress report I collaborated on. The hardware was designed specifically for the ET-137 Intertank that flew with STS-133. The fixture was used during the effort to repair and qualify the tank for flight, after a fracture was found in the stringer at the rivet line.

Hardware description:

This test fixture is designed to test a one-stringer section of STS External Tank panel under loading conditions similar to those experienced during tanking. The simulated loads are experienced when the bottom of the tank contracts under the cryogenic thermal load, but the top of the tank is at ambient temperature. This fixture uses mechanical means to deliver the simulated load without applying any actual thermal load to the test panel. The loading is intended to cause cracking in the stringers similar to that of the flight article.