ROLLER SUPPORT , 2

[malikasal]

to make a long story short, i am looking for the expert`s thoughts regarding this suggested roller support (or may i say, ATTACK) :

ôIf you don't build your dream someone will hire you to help build theirs.ö

Tony A. Gaskins Jr.

 

[mmarlow]

Ive tried to do something like this before, in an exterior application, and my superior had concerns with the slot being blocked by something.. Ice, material from industrial facility, etc..

In my situation it made sense to try a different type of connection. In yours this may be appropriate.

-MMARLOW EIT

 

[CANPRO]

Before you can get an expert opinion, you need to provide much more info:

You've stated in you need this to act as a roller - do you also need longitudinal movement in the slot?
What are the loads involved?
Is that a smooth pin or a bolt?
What is the scale of this thing? Dimensions?

Unless you're looking for opinions on the quality of your screenshot, you're not going to get anything useful based on the info provided.

 

[malikasal]

CANPRO , thanks for the input.

You've stated in you need this to act as a roller......? [highlight #CC0000](yup, this connection is supposed to allow a movement of 50 mm each side)[/highlight]
What are the loads involved? [highlight #EF2929]it is supposed to withstand a vertical shear of 2000KN[/highlight]
Is that a smooth pin or a bolt? [highlight #EF2929]a smooth pin was proposed[/highlight]
What is the scale of this thing? Dimensions? [highlight red](the slot dimensions are 302mmx102mm )[/highlight]

i am arguing with a colleague regarding this connection, i just do not like the mechanism that the movement is supposed to occur, with that huge vertical load, i am assuming that the plate will some how see some sort of distortion that will eventually clog the path of the pin.

my goal from this post is to back my opinion with the experts thoughts in this forum, hope the info now is enough.




ôIf you don't build your dream someone will hire you to help build theirs.ö

Tony A. Gaskins Jr.

 

[TehMightyEngineer]

The bridge guys figured out all kinds of heavy pin and roller bearings and their various uses and strengths. I'd look at those and most of the testing data is freely available and some DOTs or the FHWA can get you details and design recommendations most likely.

Seems like a perfect use for a bronze slide bearing under a pin support.

Ian Riley, PE, SE
Professional Engineer (ME, NH, VT, CT, MA, FL) Structural Engineer (IL, HI)

 

[BridgeSmith]

For bridge bearings, steel reinforced elastomeric bearing pads are the go-to for accommodating the vertical load and translation you mentioned, if the rotation required is small enough. For larger rotations, combined with translation and high vertical loads, the older rocker style bridge bearings might be an option.

 

[CANPRO]

I agree with your concerns about the limited longitudinal movement. I also agree with TME and HotRod10 that looking at typical bridge supports is probably the way to go. If you want/need to avoid a purchased bearing and you want to fabricate everything custom, maybe the sketch below is a better solution.

 

[JoshPlumSE]

It's been 15+ years, but during my time in heavy industrial work, we used teflon bearing plates to accommodate longitudinal expansion. Anchor rods were in slotted bolt holes I believe. Seems like a much simpler connection that what you're showing.

That being said, when you rely on bearing plates like this you do get some longitudinal force resistance (up to the normal force time friction coefficient).
So, this worked really well for our application which did not have high vertical loads.

 

[malikasal]

thanks for the input guys,
and CANPRO, THANKS FOR THE DETAIL, I WILL DEFINITELY CONSIDER THIS ONE .



ôIf you don't build your dream someone will hire you to help build theirs.ö

Tony A. Gaskins Jr.

 

[Tmoose]

What are the pin and plates made of?

As a start, simply by inspection, 450,000 lbs on ~ 4"Ø roller looks like trouble contact/Hertzian stress wise, even if the roller and plate are hardened like roller bearing components.
Your comment "I am assuming that the plate will some how see some sort of distortion." This sounds like the same concern."

https://www.engineersedge.com/material_science/rollers-contact-stress-3.htm

 

[KootK]

i am assuming that the plate will some how see some sort of distortion that will eventually clog the path of the pin.

Good call. Plowing is the death of these things when any serious vertical stress is developed.