How can I calculate hole numbers for plate support??? 1

[Saver2008]

Hi everybody!

I want to calculate the minimum hole numbers for a plate that is going to support a tube working as a bending case. I´m goint to set this steel plate on wall and on it, a pipe will be welded at centre of the plate, and this pipe will have a bending load. So in order to have the pipe with the plate supported on wall, i require to put bolts, so i need to drill this plate. so How can I calculate the minimum number of holes in order that can support without problems. I´ve checked in other topics here minimum length between edge of plate and centre of hole but for calculating number of holes...can you help me with this?? I litlle guideness to calculate that please???

Thank you very much!
Roland Saver

 

[swearingen]

Put a thousand holes. It's a nice round number and I'm sure that would do it.

Seriously, though, your question depends on a number of factors. How thick can you or do you want to go on the plate? What are the limits of the plate width and length? Are there any side or torsional loads to deal with? What about construction loads? Is this plate mounted on concrete? Wood? Ice?

Please provide more information...


If you "heard" it on the internet, it's guilty until proven innocent. - DCS

http://www.eng-tips.com/supportus.cfm

 

[MintJulep]

One.

 

[Twoballcane]

I think the question you should be asking is how many bolts you should be useing, because holse will not hold anything :+). You will have to calculate your torque and vertical forces and then from there you can calculate your tensile and sheer stress. Compare that to your yeild stress on the material you are using both plate and bolt, and then figure out what factor of safty you want. This will lead to how many bolts to use.

Good luck!

Tobalcane
"If you avoid failure, you also avoid success."

 

[Twoballcane]

Oh to add, if you have your old Shigley book or find one, it all be in there.

Tobalcane
"If you avoid failure, you also avoid success."

 

[Saver2008]

Hi everybody!

Thank you all of you. Swearingen, My initial data are:
Plate on concrete wall
Plate thickness: 3/8"
Material: ASTM A-36
Width=Length = 4" x 4"

It is a pipe sch 40 (1" nominal diameter) welded at the centre of square plate. It will work as a horizontal beam in cantiliver. I´ve got the force with shear forces and momentums and with this, the maximum momentum for calculating maxium shear strees for a tubular section cross is 766.853 lb/in2. This value, I will use it of for maximum stress in the plate with the bolts (thanks twoballcane)For this moment I have supposed 4 holes of 1/2" diameter. But before calculating it, I want to know if exists a method of calculatin number of these.
What do you think?

Roland Saver

 

[MintJulep]

Assume whatever number of mounting bolts you care to use.

Calculate the loads that could exist at each mounting bolt location.

Select bolt diameter and grade accordingly.

Don't forget to check if the wall is strong enough.

 

[chicopee]

Any variable not discussed is the strength of the concrete to hold the bolts.