Roll Cage Materials

[OutCell]

I am designing a Roll Cage (Using CAD+FE) and trying out new materials for testing/analysis. Commonly used materials i found are:

* CDS Carbon Steel
* ERW Mild Steel
* DOM Mild Steel
* Cr (Chrome Molybdenum) Steel
* T-45
* 1020 Grade Mild Steel CDW


Anybody knows any other suitable material i could use? It would be highly appreciated http://fsae.com/groupee_common/emoticons/icon_smile.gif

OutCell

[Christopher Catto]

I think you've got enough there to keep your FE package busy for a while.

ERW I believe is not suitable for an FIA cage but check the rules (i forget). You can fab uprights and stuff with ERW box section but dunno about parts of the chassis...

CDS commonly used in many forms of racing, reasonably good!

For FSAE U will not save wt in the main and front rollhopp by using better steel since rules mandate a certain thickness.

I would go for T-45 for the chassis but it's expensive. See if you can find the stuff before doing FE unless u're doing it just for a project.
Chromoly used by many teams also

1020 is the cheapest if your team is starting from scratch. Chassis will cost peanuts and will be about 2-3kg heavier but depends really...

Dunno much about DOM, but maybe I know it under a different name.

[Kirk Feldkamp]

Originally posted by Christopher Catto:
Dunno much about DOM, but maybe I know it under a different name.

"seamless mild steel"

[OutCell]

Originally posted by Christopher Catto:
I think you've got enough there to keep your FE package busy for a while.

ERW I believe is not suitable for an FIA cage but check the rules (i forget). You can fab uprights and stuff with ERW box section but dunno about parts of the chassis...

CDS commonly used in many forms of racing, reasonably good!

For FSAE U will not save wt in the main and front rollhopp by using better steel since rules mandate a certain thickness.

I would go for T-45 for the chassis but it's expensive. See if you can find the stuff before doing FE unless u're doing it just for a project.
Chromoly used by many teams also

1020 is the cheapest if your team is starting from scratch. Chassis will cost peanuts and will be about 2-3kg heavier but depends really...

Dunno much about DOM, but maybe I know it under a different name.

DOM is almost the same as ERW. Thanks for this info mate
It is for a project i am doing, i am not actually going to be building this cage http://fsae.com/groupee_common/emoticons/icon_smile.gif

[2001dodgert]

DOM is 'Drawn Over Mandrel', a.k.a. CDS.
DOM/CDS is seamless/unwelded, so is not prone to split along the weld, therefore stronger.

[Michael Royce]

Below is the information I posted answering Outcell's question under the same topic title in the "Off Topic" section of the forum.

"It seems as though when it comes to roll cage materials (and basic steel tubing) a number of people confuse the manufacturing processes and the actual materials.

ERW, DOM and CDS are different processes of manufacturing the tubing. Mild steel, alloy steel, 1020, 4130, T45, Chromoly, etc. all refer to the type of steel, the material from which the tubing is made.

Here are some basics.

Manufacturing Processes
− Tubing is a pipe or hollow cylinder. The terms "pipe"� and "tubing"� are almost interchangeable, although "tubing"� implies tighter engineering requirements than "pipe"�. Both "pipe"� and "tubing"� imply a level of rigidity and permanence, whereas a "hose"� is usually portable and flexible.
− ERW – is Electrical Resistance Welded tubing. Flat stock is formed into a tube and them resistance welded along the joint.
− DOM – is Drawn-Over-Mandrel tubing. DOM tubing does not have to be seamless. It is usually made from electrical-resistance-welded (ERW) tube that is cold drawn through a die and over a mandrel to create such characteristics as dependable weld integrity, dimensional accuracy and excellent surface finish.
− CDS – is Cold Drawn Seamless tubing. Seamless tubing is produced by extrusion. The steel, in the form of a billet, is pushed and/or drawn through a die of the desired shape.

Types of Steels
There are many, many different types of steels. But for Formula SAE we usually deal with two types, "mild"� steel and "low alloy"� steel.
− "Mild"� steel is classed as a "low carbon"� steel, with typically less than 0.3% carbon by weight. It typically contains a little (0.1-0.5%) silicon (Si) and a little (0.3-0.9%) manganese (Mn) as well.
− It seems as though every country has its own alphanumeric designations for steels. In the USA we use the 4 digit American Iron and Steel Institute (AISI) or SAE designations, such as SAE 1020 (or AISI 1020) and SAE 4130.
− 10xx denotes a plain carbon steel with less than 1.0% manganese.
− SAE 1020 (AISI 1020) is a non-corrosion resisting, plain carbon, "mild"� steel, with 0.18-0.23% carbon, 0.15-0.30% silicon and 0.30-0.60% manganese by weight.
− 41xx denotes a Chromium-Molybdenum alloy steel.
− SAE 4130 (AISI 4130) is a non-corrosion resisting, "low alloy steel"�, containing 0.28-0.33% carbon, 0.15-0.35% silicon, 0.8-1.1% chromium (Cr), 0.4-0.6% manganese and 0.15-0.25% molybdenum (Mo) by weight. It is often referred to as "Chromoly"�.
− T45 is a UK, Carbon-Manganese, "aircraft"� alloy, containing 0.17-0.25% carbon, 0.10-0.35% silicon, 1.30-1.70% manganese, 0.25% max. chromium, 0.40% max. nickel and 0.10% molybdenum by weight.

As far as mechanical properties are concerned, it all depends! Not only do they depend on the type of steel that is used, but they also depend on other factors such as the heat treatment, and whether the material has been "cold worked"�. I am not a metallurgist, but one has to think, for instance, that DOM tubing has higher tensile strength than ERW tubing of the same material, as the former has been cold worked by going through the DOM process.

[vreihen]

The terms "pipe"� and "tubing"� are almost interchangeable, although "tubing"� implies tighter engineering requirements than "pipe"�.

Tubing size is measured by outside diameter (OD), whereas pipe diameter is measured by inside diameter (ID). You will need different dies to bend a 1" pipe and a 1" tube, because the OD is different. Doesn't sound "almost interchangeable" to me..... http://fsae.com/groupee_common/emoticons/icon_smile.gif

[OutCell]

Thanks guys

I finished selecting the materials and i am off to the designing and FEA of the roll cage..

I choose different types of ERW, DOM, and Chromoly.. http://fsae.com/groupee_common/emoticons/icon_smile.gif

[BilletB]

Originally posted by 2001dodgert:
DOM is 'Drawn Over Mandrel', a.k.a. CDS.
DOM/CDS is seamless/unwelded, so is not prone to split along the weld, therefore stronger.

DOM is NOT seamless. ERW and DOM are both ASTM classification A513 which means electric resistance welded tube. Both are formed from strips and welded. DOM is then cold worked (drawn over a mandrel) to exact specifications and dimension and is noted most often as A513 type 5. There are other A513 types of DOM and ERW is a type as well. Seamless is a totally different animal and is ASTM classification A519 and is basically shaped by piercing solid stock to make the tube. A519 can be any material as well and is most often found in 1020 and 4130.