Quote:
Originally Posted by Brian_R
The long fasteners allow the whole tube to be preloaded compressively. This should give some additional rigidity and resistance to bending.
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No,
that's not really what's going on. In fact, loading the ladder bar in compression will make it
more sensitive to perpendicular loads!
Here's a better explanation:
Quote:
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The compression forces, commonly called preload, determine to a degree how stiff the joint is because immense friction is created at the part interface thanks to those compression forces. The basic idea is that the preload force must be overcome before the structure will even begin thinking of maybe shifting, just a tiny bit. Hence, properly designed machine structures are predictably stiff in their operating regimes.
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