I welded a bracket that failed on our life test machine so that we could continue the test of other components, while the bracket is being redesigned. I had to plug weld a back up plate inside the tubing to replace the missing chunk of metal. I replaced the original fillet welds with bevel groove welds to get full penetration, to improve the weld strength.
Picture 1 shows the hose routing on our machine. The bottom of the hose bracket was originally horizontal. The force of the hoses causes the broken bracket to bend down about 25 degrees. Using a bathroom type scale it takes about 100 lbs to make the bracket horizontal.
Picture 2 is the other side of the bracket. You can see that the crack is open on the top.
Picture 3 shows the broken bracket on my bench.
Picture 4 shows that the fracture started on the lower left side of the weld shown in the picture 4 and the close up picture 5 and then propagated across the weld. In picture 4 you can also see the ratchet marks as the crack propagated across the lower weld from left to right. Picture 6 shows the other tube, with the crack propagating across the top weld from left to right. On the upper right corner you can also see the bent metal and the crack on the last portion of the tube to fail.
Picture 7 is a close up of the bent portion of the tube.
Picture 8 is my weld setup.
Picture 9 is the inside weld showing the plug welds for the back up plate.
Picture 10 is a close up of the inside weld.
Picture 11 is the outside weld.
We are currently in the process of redesigning the bracket to make it stronger.
We were thinking of a couple of options:
- Making it out of a solid bar and bending it.
- Specifying a bevel groove weld followed by a fillet weld to get full penetration and then heat treating the weldment to bring it back to the T6 condition.
Any other ideas?
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Thread: Broken Hose Support Bracket
10-08-2011, 04:05 PM #1Senior Member
- Join Date
- May 2008
- Troy, MI
Broken Hose Support Bracket
Smith Oxyacetylene Torch
Miller Dynasty 200DX
Clausing/Coldchester 15" Lathe
16" DuAll Saw
15" Drill Press
7" x 9" Swivel Head Horizontal Band Saw
20 Ton Arbor Press