Welded Connection - Fixed on FBD
Welded Connection - Fixed on FBD
(OP)
A member of the shop had fabricated a lifting attachment from HSS tubing. If the part of the device are two sections mitered at 45 and welded together are these still considered two sections with the weld joint being a treated as a fixed support or one section in a FBD?





RE: Welded Connection - Fixed on FBD
RE: Welded Connection - Fixed on FBD
To fully construct a FBD would you consider this as three sections, (AB, BC and CD)with the nodes at B and C being fixed?
RE: Welded Connection - Fixed on FBD
Have a look at this site for weld calculations where the weld is treated as a line.
Not sure I like screwing the lifting lug into the welded nut because its only to the top surface of the box section.
I would first of all treat the lug as one and use strain energy methods to get deflection etc, I would then analyse the welds seperately for failure in shear on the fillet welds due to tension and bending, incidently your welds at the mitred corner can't be fillet welds as the two faces are flush.
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RE: Welded Connection - Fixed on FBD
RE: Welded Connection - Fixed on FBD
I'll have a look at your drawing and post a bit later.
How much analysis on it have you done so far? and as it been tested yet in the shop.
I think also it would be wise to add some plates at the square corners as there likely area's to be stress raisers.
desertfox
RE: Welded Connection - Fixed on FBD
RE: Welded Connection - Fixed on FBD
https://s
and buy these three books:
1) "Procedure Handbook"
2) "Design of Welded Structures"
3) "Solutions to Design of Weldments"
These are all massively subsidized and far cheaper than you could find comparable books on the subject. And the best one is the one that is the cheapest at only $3.50, which is the "Solutions to Design of Weldments."
As for your problem, you can probably get by with it as-is if it passes a load test then an NDE on the welds. Gussets would probably help if your welds crack.
But if it were me, to get a good connection at the knees, I would put a plate in the middle of the members like is done on the sign in the following link:
http://ma
This is an example of a properly-designed knee between two HSS members. Though with the loads you're dealing with, you'll probably be OK. Just test it and subject it to regular inspection. Also do something to keep water from collecting inside if that's a possibility.
Engineering is not the science behind building. It is the science behind not building.
RE: Welded Connection - Fixed on FBD
Engineering is not the science behind building. It is the science behind not building.
RE: Welded Connection - Fixed on FBD
I would definitely add the gusset plate at the mitred corner, as this creates a load path for reacting the bending moment.
EngineerTex,
A star for you, for the best use of Google Maps to provide an example of good engineering design!