Yeild Line Theory for steel plates
Yeild Line Theory for steel plates
(OP)
Hi all
As part of a steel connection design, I have to check a rectangular steel plate supported on 3 sides. The plate is 180mm x 195mm with a bolt hole in the middle.
The plates supports a fixed/continuous.
I would like to use the yield Line theory to check the plate thickness to get a bit more economy.
Does anyone have a typical design example.
Many thanks
Charlie.
As part of a steel connection design, I have to check a rectangular steel plate supported on 3 sides. The plate is 180mm x 195mm with a bolt hole in the middle.
The plates supports a fixed/continuous.
I would like to use the yield Line theory to check the plate thickness to get a bit more economy.
Does anyone have a typical design example.
Many thanks
Charlie.






RE: Yeild Line Theory for steel plates
Be sure to consider the deformation of the plate. With some connections, it's possible to come up with a very thin plate, but it would take a huge displacement to achieve the YL mechanism. In some cases, this is no good, of course. It is impossible to get the deflection from the YLA. A FE model of the part is usually very fast and easy to build and use to check deformation. Approximate manual calcs can also be done to get the deflection.
RE: Yeild Line Theory for steel plates
Thanks for the advice. I'm using a design guide from the Reinforced Concrete council called 'Practical Yield Line Design' downloaded from the net.
This uses the 'work' method where external energy expended by the displacement of loads is equated to the internal energy dissipated by the yield lines rotating.
From this I can get the moment on the plate.
I've managed to follow this through but just wanted to see if anyone had any examples to make sure I've got the method correct.
I understand what you mean about making the plate too thin will try and check using FE analysis package in the office.
RE: Yeild Line Theory for steel plates
RE: Yeild Line Theory for steel plates
Apologies but I have a bit of difficulty following your illustartion. I get the general 'jist' of it
Attached is my effort, this follows a concrete design example, but is for a steel plate.
The deflection of the plate is taken as unity. The sagging moments are taken as being equal to the hogging moments.
l is the yield line length less the hole radius.
Would it be possible to give this a look over. I was hoping to get a smaller answer.
Many thanks for the assistance.
Chas
RE: Yeild Line Theory for steel plates
RE: Yeild Line Theory for steel plates
The formula I've used are from the concrete design example I've followed...............so I'm not sure..........I suppose this explaines the reason for my post.
Once again ...........Many thanks
Chas
RE: Yeild Line Theory for steel plates
Your calcs are neater than mine... FYI, the plastic section modulus is bd^2/4 and provides a slightly larger margin of safety. Great example.
Dik
RE: Yeild Line Theory for steel plates
Dik
Many thanks for the assistance. If I use the plastic modulus it gets the plate thickness down to 21mm. which is nearer the number I was thinking about.
Many thanks
RE: Yeild Line Theory for steel plates
Dik
RE: Yeild Line Theory for steel plates