bodyman5000 and 1
Lions, Tigers, Me, Bears
- Joined
- Sep 29, 2013
- Messages
- 19,582
- Likes
- 13,216
- Points
- 113
Do it all the time. Drill off a panel that is spot welded and there are a few pieces of weld left.Yes, I really really hate to see my young ones get on some of this shit they call rides. Especially the older stuff, as they just use it until it fails.
Some of these should be forcible retired.
And going back to what that Cal trans Engineer said that was so blatantly bad, the yield might be low but the ultimate strength is the same.
Well think over you pin while I make a few points.
Steel actually gets stronger with use over time, IF the yield in never exceeded. Yield is the stress point where the metal begins to deform. It can bend or flex to this point, stretch to this point and return to the original shape. If it stresses exceed the yield strength then it will permanently deform in shape. In either case, steel work hardens as it flex and be comes stronger, probable flexing less with the increased hardness but still returning to the original shape. Deforming it also gets harder but it does not return to the original shape of it's own metal memory. It is deformed back again by stresses and hardening some more. This process does not take long before it is too hard and cracks reducing the cross section of materials resisting the load until failure occurs catastrophically. Bang!
It is also well know that even while staying within yield or plastic load flexing, and the associated hardening, there is a cycle life to this process where too many cycles will harden the steel to the cracking point. So it is a matter of time and how rapid the cycles occur. Cycle once a day, probably Centuries of duty, but 5 a second and you better predict the failure time and replace well prior to that. Variations in between.
You have no doubt used this before, bending a hunk of wire back and forth until you break off a length.
I also have to be aware of heating anything while repairing it.


