Calculating force to bend a rod?

[Kevin Sevcik]

Originally Posted by Pavan

This doesn't answer your question but your question sparked my question. What advantages do a single bent piece have over two pieces cut and welded to make the part?

Simply put, the primary advantage is that you don't have to weld it. Welding is wonderful for joining two pieces of metal, but most all welds are weaker than a solid piece of material for a few reasons. First, your weld has to be perfect. Any voids or cracks in the weld compromise its integrity in the long run. Second, welding is HOT. When you weld, you're basically melting your two parts together and adding extra material to make up for any gaps and to provide some extra material to reduce sharp corners. This means that the material around the weld is getting very hot. So all around the weld is an area of material you've just applied an impromptu and fairly uncontrolled heat treatment to. This is the Heat Affected Zone (HAZ) which you've basically just air quenched and softened by a good bit.

Finally, sharp corners are bad. Any sharp corner anywhere inevitably concentrates stress at that point and weakens the joint. So a large radius bend will hold up much better to load than a weld with a small fillet on it.

As with everything there's plenty of other things to be concerned about with welds like hydrogen sulfide cracking and other corrosion issues and... well. lots of stuff that doesn't come up much in FIRST bots.