Carbon Fiber vs Steer Steering Column Supports

[Loga1919]

I am currently part of a collegiate-level design team, designing a steering system for an offroad car. The previous year's car supports were essentially made of 2 cantilever hollow steel tubes which then connected to a spherical to constrain the column. I want to keep this design but change the material from steel to carbon fiber. There was a noticeable amount of deflection last year, which I want to mitigate but also reduce the weight. I want to make sure the amount of deflection is less than what we saw with the steel tubing in the previous years. When it comes to carbon fiber tubing, is carbon fiber typically stiffer than steel. I am seeing different results depending on different types of carbon fiber, so what kind would be best for this application?

[lo_0l]

14 hours ago, Loga1919 said:

I am currently part of a collegiate-level design team, designing a steering system for an offroad car. The previous year's car supports were essentially made of 2 cantilever hollow steel tubes which then connected to a spherical to constrain the column. I want to keep this design but change the material from steel to carbon fiber. There was a noticeable amount of deflection last year, which I want to mitigate but also reduce the weight. I want to make sure the amount of deflection is less than what we saw with the steel tubing in the previous years. When it comes to carbon fiber tubing, is carbon fiber typically stiffer than steel. I am seeing different results depending on different types of carbon fiber, so what kind would be best for this application?

 

It sounds like what you're after is rigidity to minimize deflection. For carbon fiber, this depends a ton on the weave, wall thickness, and material. For steel the same applies but no weave - so the material choice and wall thickness are paramount. Rock West Composites has lots of off-the-shelf carbon fiber tubes that might be a good fit. Depending on your budget it might also make sense to have something woven to your spec.

There are a number of tools out there that will help you calculate this. This would be a great project to partner with another department or student on to help you with the equations if you're not comfortable with the math 🙂