Water freezing in HSS Column 1

[tmlim]

Does anybody know of any resources regarding the effect of water freezing in side an HSS column??

 

[tmlim]

@Stillerz
They are 178mm x 178mm (7" x 7")

Also, here in Canada some square HSS are formed from cold-forming a circle section to a square section.

 

[Stillerz]

I guess I entirely misinterpreted the "squeeze" term.
Our parent company owns a tube mill, and I have seen it run.

 

[BAretired]

tmlim stated:

Unfortunately, one of the columns has deformation for almost the entire length of the column.

I am having trouble understanding this statement. Does that mean the column was totally filled with water?

If you drilled some drain holes near the bottom of the column, would it be possible to prevent water from accumulating inside the column? If you can prevent future freezing inside the column, then I tend to agree with hokie that there is no reduction in capacity, but before committing fully to that theory, I would like to see a photo of the column which is deformed throughout its length.

BA

 

[paddingtongreen]

Stillerz, sorry if you thought I meant a very big vice, I meant by rolling.

There are going to be local Pdelta effects, but I took this to be a "long" column, where the column stress is based on kL/r, not the limits of the material.
I have performed analyses of such cases, introducing the the offsets and modified section properties at the appropriate places. The effect on the column buckling load was negligeable, and the local material stress limits were not exceeded by the local Pdelta effects.

Michael.
Timing has a lot to do with the outcome of a rain dance.

 

[tmlim]

@BAretired
Yes, the column was nearly entirely filled with water. We are taking measures to make sure this doesn't happen again, but we need to assess the current deformed column and what needs to be done.

I will try to get some photos for everyone to view.

 

[tmlim]

I thought I would just give an update on what we've decided.

Myself and my boss, also a structural engineer, have come to the conclusion that the deformation in the column will not affect the intended design function except at the base of the column. (I've been an engineer for almost 7 years, and my boss has been an engineer for over 30 years.) We will be reinforcing the base of the column with gusset plates welded to the column and the baseplate.

Here are some of the reasons:

1. The column has a factored capacity of 1200kN. The factored load on the column is only 400kN. The column is over-designed.

2. I've done some computer modeling of the deformed vs original column. The increased local moments and forces did not increase a significant amount and is still within capacity of the steel.

3. The section modulus would not decrease with the new shape. Technically it would increase, but I don't want to consider this in my analysis.

4. Deformation of the column is approx. 20mm from original shape on all 4 sides and there were no signs of any fractures.

5. My boss says that the steel itself would be strong by way of working the steel from the deformation, but I choose not to consider this in the analysis.

Naturally we will keep an eye on the affected columns to make sure there is no more changes in shape, but the initial water freezing in the column will not happen again. The column is sealed and there are also holes in the bottom that was drilled to drain the water.

Thank you to everyone for your input and please feel free to continue sending opinions. I've enjoyed debating this subject.

 

[hokie66]

tmlim,
Thank you for the update. I believe your decision is appropriate.

 

[BAretired]

I can't argue with your decision either.

BA

 

[tmlim]

@hokie66 @BAretired

Thanks! Always good to hear!!