×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Distorsion of HSS Tube

Distorsion of HSS Tube

Distorsion of HSS Tube

(OP)
Can someone please offer there insite, here is my situation:

HSS TUBE 4" x 4" x .500"w x 220" Long
Has been machined on 2 sides the full length of the tube with a strip 1" wide by .250" deep.

The HSS was flat when shipped. Was shipped in a truck and sat in the truck for approx. 2 hours at 0 Degrees Celsius (32Fa).  The beams were off loaded from the truck  and placed on a cart (approx 3ft x 4ft) in the middle of the
beam, inside at room temperature.  The beams are now bowed (close to 1") from one side to the other.

I am not an expert on the states of steel or the changing properties of HSS tubing but is it possible and can distortion this extreme happen with the conditions listed above?
 

RE: Distorsion of HSS Tube

(OP)
Forgot to add that there was aprox. 5-10LBS steel brackets welded on either both ends.

RE: Distorsion of HSS Tube

Hi rapps

I suspect that the steel tube warped because after machining the residual stresses locked up in the section redistribute themselves.

desertfox

RE: Distorsion of HSS Tube

Hi again

Also the welding of the brackets would cause distortion, how do you know the HSS was flat when it was shipped?

desertfox

RE: Distorsion of HSS Tube

(OP)
the tube was indicated when machining, the handling was from machine to floor (flat) not placed on horses or wood, simply layed on the concrete.

RE: Distorsion of HSS Tube

Was it clamped down for machining when it was indicated? The tube is flexible so how does the distortion affect the function of the tube? Will it be clamped to other structure so it will be whatever shape it gets clamped to?

RE: Distorsion of HSS Tube

(OP)
at this point it cannot be used because a linear rail will be bolted onto the machined flats.  

RE: Distorsion of HSS Tube

Hi rapps

You need to provide more information ie :- a sketch or drawing would help and some information about what the tube is being used for, drip feeding the information post by post isn't helping us to help you.

desertfox

RE: Distorsion of HSS Tube

(OP)
i will post a drawing on monday

RE: Distorsion of HSS Tube

hi rapps

Just done a quick calclation, assuming the beam was uniformly loaded ie by its own weight and simply supported, I get a deflection of nearly 11" at the centre, however the stress is still within the elastic range and therefore should not have a permanent set, so I believe if you have distortion on a permanent basis this would have occured during manufacture.
Please check my calcs I did it in a hurry in my lunch break.

Desertfox

RE: Distorsion of HSS Tube

How were the pieces clamped during machining. Was the machining done in stages? Also finally for the finish cut,were soft jaws used. There has been a buildup of internal stresses during machining resulting in a permanent bow.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources