Testing Composite Tube (WIP)

Carbon-fiber tubing presents a very desirable solution to rotational and axial load transfer in pushrods, tie-rods, and steering columns because of how light they are compared to metal tube. However, unlike metal, composites are not isotropic. They handle different loads differently under different loading conditions and directions, and they can vary wildly from supplier to supplier, and therefore it is extremely difficult to do accurate hand calcs or FEA on these parts. As such, if you intend on using composite tube in your dynamics system, you should do testing on the specific rods you purchase to ensure that they are safe to use. As mentioned, you must do separate testing to determine their behavior in different load cases.

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Torsional Loading

Torsional testing must be done to determine the viability of using composite tubing for rotational power transfer in steering systems. When the driver turns the steering wheel, rotation is transferred through the steering linkage to the pinion gear of the rack. However, when the rack is at its max translation the linkage will no longer be able to turn, and any torque that the driver puts on the steering wheel will be met by a reaction force at the opposite end of each shaft. Therefore, it is important to make sure that whatever tube you use can sustain the torsional load of a panicked driver turning on a steering wheel that can no longer turn.

Tensile Loading