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Old 02-18-2015, 09:53 PM
Bushwacker Bushwacker is offline
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Quote:
Originally Posted by keith View Post
. . . My question is about drilling another hole in the side of the boat that will have to be within 4-5" of the existing hole. Is this ok? How close is too close? . . .
Depending on the stress field, a couple of smaller holes (known as shielding holes) adjacent to a larger hole can actually reduce the concentrated stress around the large hole! It's common practice to install such holes between bolt holes in the flanges of compressor and turbine disks on gas turbine engines! The extra holes cause the loads and stresses to redistribute so there are more gradual changes between holes such that the maximum concentrated stresses at the edges of the big holes are significantly reduced. You can find some guidelines for stress concentration factors vs. hole size and spacing in a Machine Design textbook or a Mechanical Engineering Handbook.
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