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Unread 23-02-2010, 13:37
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Re: GDC at it again!

And the GDC is at it again... http://forums.usfirst.org/showthread.php?t=14758

Quote:
Given that plywood is a non-homogeneous, non-isotropic material with the strength and bending moment determined, in large part, by the relative orientation of the surviving laminations, it is not at all clear that cutting a dado across the entire height of the material would not severely compromise the structural integrity of the material. The dado reduces the effective thickness of the material by 16.67%. To ensure that the integrity of the modified plywood backing is still sufficient to survive the expected impacts of a typical match, you will need to provide appropriate analytical results to allow us to perform a comprehensive stress-loads analysis prior to having your robot inspected at the competition. As a minimum, we will need the following materials to be submitted for review: a clear definition of the resulting neutral axis along the entire length of the modified plywood material, a Finite Element Analysis (using a NASTRAN-compliant tool or equivalent) of deformation of the plywood backing within 12 inches of the dado cut during a 40-G impact by a 150-pound robot, both analytically- and experimentally-produced predictions of the yield strength of the modified plywood, and a full analysis (using Timoshenko beam theory or equivalent) of the resulting beam stiffness at the moment of impact as compared to the theoretical yield strength. ---- Nah, just kidding. Your solution sounds fine. No problem.
By far my favorite answer of the build season.
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