Shear vs Bending force
Shear vs Bending force
(OP)
A rectangluar beam of 1.25" High x 1" Wide (Area = 1.25 sqin)
the beam is only 1" long
force is evenly distributed along 1" x 1" face
Beam is rigidly mounted to wall (Figure its a part of the steel wall machined out, so like a block sticking out)
is the block in shear or bending or both?
I thought there was some sort of ratio when figuring this stuff that if the Beam height is more the the beam length than the object is only in Shear.
the beam is only 1" long
force is evenly distributed along 1" x 1" face
Beam is rigidly mounted to wall (Figure its a part of the steel wall machined out, so like a block sticking out)
is the block in shear or bending or both?
I thought there was some sort of ratio when figuring this stuff that if the Beam height is more the the beam length than the object is only in Shear.






RE: Shear vs Bending force
RE: Shear vs Bending force
RE: Shear vs Bending force
RE: Shear vs Bending force
RE: Shear vs Bending force
RE: Shear vs Bending force
Yes the member is in both shear and bending. I agree with strucengnr, 0321 and fishercd on the domianace of the shear and bearing. Due to the size of the section I would consider it as a machined part and not a structure. Enshure you include appropriate allowable stress reductions for welding, fillet radius, size, and stress concentrations.
Cheers
RE: Shear vs Bending force
Why is a "machined part" treated differently than a "structure"? In this case a one member structure. And, for the same steel material, are the allowable stresses different? If so, where do I find that information?
I've always wondered what those "Mechanical Guys" (as in ME's) do for a living <G>.
RE: Shear vs Bending force
Cheers
RE: Shear vs Bending force
Thanks for clearing that up, we're back on the same wavelength!
RE: Shear vs Bending force
People pay us the big bucks to be practical, and efficient.
I would call that part a shear lug, by the way. If you want to get into details about the nomenclature of structure type, maybe you could get yourself a PH D or something...
RE: Shear vs Bending force
RE: Shear vs Bending force
Area=1.25"
Fy=36,000 (assumed)
Shear=0.4 x Fy
10% ~ 1,800 lbs
RE: Shear vs Bending force
RE: Shear vs Bending force
The block will be in shear and bending:-
The maximum stress from bending lies on the top and bottom surface of the block and will be tensile and compressive. This will go from max to 0 at the neutral axis.
The max stress from shear lies down each side of the block and is a parabola with the maximum at the centre. Therefore where the bending stresses are at their maximum the shear stresses are minimum and visa versa. The area in between you can combine vectorally using mohrs circle or any other method.
If the height to dept ratio is less than 5:1 then bending will dominate. Work out the bending stresses ignore the shear. Yours is 1.25:1. In the practical world work the both out and add the maximums you know it will be ok.