How to make angle iron span 2m- your ideas please

[Nathan Levin]

Hi all
I have 4cm x 4cm x4mm angle iron and need it to span 2m and support the weight of max 150kg, it bends slightly when I stand on it on blocks to check the deflection so my thinking is either
1. add a piece of 4cm x 5mm flat to the underside of the L to make a T, or
2. weld together 2 pieces of 4cm x4cm x 4mm to make a T, or
3. weld together 2 pieces of L 4cm x 4cm x 4mm to make a square tube
What do you think is the best route to create this,

Please bear in mind that this is the material available, there is no option to buy bigger angle, or a RSJ,

The only option is thicker flat

Thanks for your ideas

 

[Bornfree]

No 3 the box

 

[Agroshield]

4. Weld together two pieces of angle to make a Z-section or C-section, 4cm wide and 8cm deep.

The bending resistance of any section is proportional to its stiffness (a material property) and its geometry (specifically its second moment of area, known as I-value). Double the depth of a simple rectangular section and its bending resistance goes up by a factor of 8, so the deeper you make your 'structure' the better it will be. Making it wider has, in this case, negligible effect.

 

[Barking Mat]

Going to need reinforcing, that much is sure.

 

[Screwdriver]

Insufficient data to compute. What are the restrictions other than material?

Sounds like you want to build a truss bridge.

 

[Nathan Levin]

Thanks - like this?

 

[Screwdriver]

 

[Parm]

Is this at home or work?
One may just hurt you if it goes wrong, the other will require you to answer difficult questions

my advice. Consult an engineer experienced in such matters

 

[Benford]

I wouldn't go for option 3.
Ive used this calculator in the past for calculating deflection on projects I've worked on.

Hollow Rectangular Beam Deflection Calculator

In most building sites, hollow rectangular beams are used because they can bear the forces like hearing and bending in both the directions. Hollow rectangular beams are resistant to torsional forces, more than I-beams.

www.easycalculation.com

 

[123hotchef]

the Z gets my vote

or better still this

 

[Agroshield]

For extra credit, can you show this in two colours, one indicating the tensile members, where he can use his 40 x 5 flat and the other indicating the compression members, where the 40 x 40 x 4 angle would need to be used.

 

[Nathan Levin]

Use will be at home as a beam to span 2m

 

[Barking Mat]

For extra credit, can you show this in two colours, one indicating the tensile members, where he can use his 40 x 5 flat and the other indicating the compression members, where the 40 x 40 x 4 angle would need to be used.

Oooph, is that nescary *spelling.

 

[Barking Mat]

French autocorrect.

 

[Pigeon_Droppings2]

Pretty sure my garage roof is made of similar stuff and that's a 4m span...it's an A frame roof truss.

The roof easily holds my weigh...I was curious so I gave it a try.

2m span...can't you just use wood instead?

 

[Parm]

Use will be at home as a beam to span 2m

go With the forum expertise

 

[123hotchef]

Pretty sure my garage roof is made of similar stuff and that's a 4m span...it's an A frame roof truss.

The roof easily holds my weigh...I was curious so I gave it a try.

2m span...can't you just use wood instead?

my roof is 5M span and wood holds my weight and the mrs and the roof and the snow

 

[Bobupndown]

2m span...can't you just use wood instead?

Hard to weld...

 

[Nathan Levin]

Thank you everyone, will go with the Z option, it will be tested scientifically by me and my wife jumping up and down on it when its done to ensure it is the correct strength, I needed outside thinking because where I live its not an option to dash off to B&Q or builders warehouse I am 1500 miles from UK on an island and sometimes we need to think outside the box and adapt materials that are available to fulfil a need

 

[Pigeon_Droppings2]

You could try the "C" with 2 lengths...if it isn't strong enough then make another "C" and join them back to back to make an "I". That might be enough strength given the vertical will be double thick.