Check my statics please! Concrete embedded plate

[JStructsteel]

See attached, would anyone disagree with my thoughts? For the second option, I am thinking i should use e2' as my distance.
Thanks

 

[dik]

I would normally use a moment arm equal to the distance from the edge of the plate to the headed stud, and check the plate can take the moment from the edge of the plate to the angle.
You may not need the other headed stud., distance 'a'.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[JStructsteel]

Dik
That makes sense, but if the angle is above the bottom headed stud (my second condition), then the moment arm 'a' would be to the bottom stud (check plate bending) and the e3 would equal e2, or you saying the plate is infinitely stiff and the compression will always be at the bottom of the plate?

 

[dik]

Your second condition is largely indeterminate... what happens if you remove the first stud in your second condition? It becomes determinate. The first stud is largely wasted. The steel plate is not infinitely stiff, but likely much stiffer than the concrete.

Being a finite individual, I rarely deal with infinite things... an anecdote from an appliance salesman from decades back... his stove was infinitely temperature adjustable. He had a puzzled look when I told him that if I were to live forever, I would not likely appreciate that...

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[JStructsteel]

Thanks, I agree on the first stud being useless, but I always put them in....Just seems weird having a plate with 2 studs at the top only. Also then strengthens the plate so my bending arm in the plate is lower.

I am working on a spreadsheet, will upload soon.

 

[dik]

Why? ...not to me.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[JStructsteel]

I guess I have always done 4 studs on a bigger plate (>8" square) Gives some capacity too if a load reversal happens for some reason. Just feel better about it for me, lol.

Here is an attempt to spreadsheet the calc. I think its conservative, the angle bending doesn't include the k distance subtracted off, just the thickness for bending. Stud design will be based on tension in top row of studs.

any feedback appreciated.

 

[Celt83]

assuming this is embedded in concrete there should be no compression in the lower studs, the compression is resisted through bearing of the plate against the concrete. For Uniaxial bending See Blodgett (Design of Welded Structures) pgs 3.3-6 through 3.3-10. If you have Biaxial bending there is the Bentley white paper.

Stud design will be based on tension in top row of studs.

don't forget their share of the shear reaction.

 

[dik]

Sorry Celt... very little, but some. The axial stiffness of the stud steel in embedded compression is likely greater than the flexural stiffness of the plate. As I noted, the solution is indeterminate. I normally discount studs close to the edge for shear resistance... may as well not put them in, or do something else if you need the shear resistance. You check the top studs for combined loading, anyway.


-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik