Channel hopping

A window into the possibilities available using advanced simulation channels

- DANNY NOWLAN

One of the great things about what I do is, from time to time, I get really great suggestions from customers for potential articles. In this particular case, the customer (Supashock dampers based in Adelaide, Australia) suggested I write an article about ChassisSim’s advanced data logging channels, and how this pertains to racecar design and structural analysis. Given that this, and the use of in-depth data analysis, is a great untold story, I thought it only fitting we discuss the subject in depth.

One of ChassisSim’s great strengths is its fully transient nature, combined with a plethora of data channels. If you combine this with the software’s full, multi-body vehicle dynamic model you get an excellent snapshot of what the car is doing, which enables you to make some very informed calls on what you are doing with its set-up.

As an example, let’s consider suspension geometry and do a force analysis so you can see what you need to take into account. To start, take a look at the simulated lap trace shown in Figure 1. Now let’s briefly walk through the traces. The first is speed, the second is engine rpm, the third is steer / neutral steer, the fourth is throttle, the fifth is front tyre contact patch lateral forces in kgf, the sixth is the rear tyre contact patch lateral forces in kgf and the seventh trace is the roll centres.

The first immediate takeaway from this is the lateral forces that are returned. In any structural analysis, one of your most vexing questions is what are the loads and what do you design to? The great thing about a correlated and representative simulation model is you are no longer guessing. As we can see from Figure 1, the peak front contact patch lateral force is 514kgf, while the rear peak lateral contact patch lateral force is 606kgf.