how to manufacture an internally reinforced steel hollow-box beam
how to manufacture an internally reinforced steel hollow-box beam
(OP)
Dear all,
I´m new in this forum. I don't even know if this section is the most appropriate to post my question.
I want to manufacture a steel beam that is ribbed inside. Basically it´s an hollow-box beam, but it is not bulk along the thickness. It is internally reinforced with steel ribs. I want to know how shall I manufacture the beam. I was thinking about welding. The problem is when I "close the beam" with the outer surfaces, I can´t see the places that I shall weld. I think that by casting is also possible, by using a parget counter-mold and flowing molten metal inside. Any other suggestions about possible manufacturing methods? I would like a reference where I could study this myself, if possible. Sorry to don´t attach the geometry, but I can't really disclose it.
regards,
hmalfs
I´m new in this forum. I don't even know if this section is the most appropriate to post my question.
I want to manufacture a steel beam that is ribbed inside. Basically it´s an hollow-box beam, but it is not bulk along the thickness. It is internally reinforced with steel ribs. I want to know how shall I manufacture the beam. I was thinking about welding. The problem is when I "close the beam" with the outer surfaces, I can´t see the places that I shall weld. I think that by casting is also possible, by using a parget counter-mold and flowing molten metal inside. Any other suggestions about possible manufacturing methods? I would like a reference where I could study this myself, if possible. Sorry to don´t attach the geometry, but I can't really disclose it.
regards,
hmalfs





RE: how to manufacture an internally reinforced steel hollow-box beam
How long a rib?
What spacing of the ribs?
What is thickness of walls, and of what material?
How many do you need to build?
With what accuracy of every dimension?
Who will make the box, and for what type of client? Toys, bank safes, NASA, bridge beam, building wall, typewriter desk, pipe support, or birdbath? 8<)
RE: how to manufacture an internally reinforced steel hollow-box beam
A rib is between 30-50 cm long. The ribs are not all oriented in the same direction
a beam with section width b=0,2 m and section height h=0,3 m and lenght L=1m has 10-20 ribs in each side.
Material is construction steel. Thickness of the ribs and of the beam is 2-4 mm Total tickness of the reinforced walls is 4-6 cm
I want to build 1 to 3 beams
The geometry tolerance may be in the order of the 1-3 mm
It´s for an industrial laser cutting machine.
I hope I told enough to be able to get a solution.
regards,
hmalfs
RE: how to manufacture an internally reinforced steel hollow-box beam
Note that the usual HSS (hollow structural section) will have one or more weld seams on the inside faces, so if you need a perfectly 'flat' bore you'll have to broach it, or buy tube with the weld seam in the corner, like Telespar.
Mike Halloran
Pembroke Pines, FL, USA
RE: how to manufacture an internally reinforced steel hollow-box beam
make the tube in segments. weld the stiffeners together (or cut them from plate); stack tube segments either side and weld away ! if things need to be carefully aligned, make a tool for the stiffener pieces to fit over (around) and align the tube segments.
Quando Omni Flunkus Moritati
RE: how to manufacture an internally reinforced steel hollow-box beam
To MikeHalloran:
Sorry about my lack of knowledge about technical terms in English but what do you mean by :
-fin
-"mill slots"
"stepped on two edges"
"weld seams"
Do you have any document (.pdf for instance) that you can attach with schemes about your suggestion? Or can you post a link to the document, if it is copyrighted.
To rb1957:
What do you mean by making the tube in segments? do you mean splitting along the length in equal parts?
"stack tube segments either side and weld away"- Where shall I well? on the interface between the ribs and the Hollow-beam?
Do you have any document (.pdf for instance) that you can attach with schemes about your suggestion? Or can you post a link to the document, if if it is copyrighted.
Thanks for your help,
regards,
hmalfs
RE: how to manufacture an internally reinforced steel hollow-box beam
"mill slots" := use a milling machine to cut slots through the tube wall where you want ribs
"stepped on two edges" := not a single rectangle, but the union of two rectangles like this:
+-----------------------------------------+
| | <-- extends outside tube
+---+ +---+
| |
| | <--- rib/fin inside tube
| |
+---------------------------------+
"weld seams" := Linear projections inside the tube where the longitudinal seam(s) are|is welded in a tube mill. These are customarily removed by a scarfing cutter when making round tube where a full round ID is needed, but are customarily not removed from rectangular tube, where the ID finish is usually unimportant. The projections also occur on the outside of the tube, but are customarily removed from all types of welded tube. The projections are an artifact of the continuous tube welding process, where the seam faces are squeezed together at the weld location and some molten metal is squeezed out.
Mike Halloran
Pembroke Pines, FL, USA
RE: how to manufacture an internally reinforced steel hollow-box beam
RE: how to manufacture an internally reinforced steel hollow-box beam
If you have some good welders and a welding shop, sketch out what you need, step out to the shop and ask them "Hey, how would you go about making something like this?"
Without knowing more details, putting corrugations in the walls might accomplish the desired purpose.
RE: how to manufacture an internally reinforced steel hollow-box beam
CODE -->
+-----------------------------------------+ | | <-- extends outside tube +---+ +---+ | | | | <--- rib/fin inside tube | | +---------------------------------+RE: how to manufacture an internally reinforced steel hollow-box beam
Quando Omni Flunkus Moritati
RE: how to manufacture an internally reinforced steel hollow-box beam
I'm not sure I'm correctly picturing the ribs being oriented in different "directions."
http://www.corvair.com/gfx/otto-1.jpg
http://i.ebayimg.com/t/NOS-MONTESA-CAPPRA-CYLINDER...
http://www.steelconstruction.info/images/c/ce/R19_...
RE: how to manufacture an internally reinforced steel hollow-box beam
http://www.youtube.com/watch?v=QoF1nxKW0vw
I agree with JStephen on the possibility of other solutions. It would be good to know what the intent is and there may be some better solutions which could be suggested by many.
Since this item is not meant for backpacking or air travel, it may be more cost-effective to simply buy some heavier tubing and forget about the stiffeners. In general, machine tools benefit from the mass, but maybe yours is the exception.
RE: how to manufacture an internally reinforced steel hollow-box beam