Bending an iron bar.

[ColinBellsjockstrap]

OK, question for the Bluemoon Physics boffins,

You have two x three metre lengths of steel pipe.

One is solid

The other is hollow like scaffolding tube.

Which would be stronger, (harder to bend)

I have a friend who owns a steel supply company, and he said the hollow bar would be harder to bend.....

Agree?

 

[west didsblue]

If they are the same weight, the hollow one would be harder to bend as the solid one would be narrower. If they are the same diameter, the solid one would be harder to bend.

 

[ColinBellsjockstrap]

^Sorry, forgot to say same outside diameter...(ignore the weight)

 

[urmston]

I think the solid one would be harder to bend.

If you made a wider hollow pipe out of the same amount of steel contained in the solid bar, that would be harder to bend than the solid bar.

A solid bar of steel of one inch diameter would be much harder to bend than a steel pipe of one inch diameter with walls 0.5 mm thick.

I have kicked in a tube of an old bike frame made of steel and it buckled easily, but I doubt I'd have bent a solid tube of the same diameter.

 

[MaccJoe123]

It's to do with how to weight is spread across the pipes, if you add a weight to the two the solid one will start to bend as the stresses are more evenly spread, (the top of the bar in tension and the bottom in compression), however it doesn't mean the hollow one is "stronger" as if you increase the weight it will snap easier than the solid one.

 

[abu13]

A hollow tube is harder to bend if you need to keep the profile, you would need a madrel to hold the form

 

[peoffrey]

Anyone got a photo of a cat that looks like Hitler?

(I joke.)

 

[Summerbuzz]

I think the scaffolding guy might be working the weight of the bars into the equation. Solid steel supporting the weight of solid steel might be closer to breaking point than hollow steel supporting the weight of hollow steel.

 

[Pelly Greeny]

Do you mean tensile strength or axial compressive strength?

 

[smudgedj]

OK, question for the Bluemoon Physics boffins,

You have two x three metre lengths of steel pipe.

One is solid

The other is hollow like scaffolding tube.

Which would be stronger, (harder to bend)

I have a friend who owns a steel supply company, and he said the hollow bar would be harder to bend.....

Agree?

LOL You can't have a solid pipe.