Force based analysis

[hutch325]

I'm looking to analyze the suspension of a vehicle that is essentially SLA front and rear, on a force based basis. The goal is to determine lateral load transfer as a function of lateral acceleration, accounting for changing installation ratios, nonlinear spring rates (springs in series, in parallel with bumpstops), and other interesting things.

I haven't found a solution example in RCVD or similar so I drew a FBD and started writing equations.

I would like to implement the solution numerically using Excel (nasty I know). I have access to Matlab but only at work and on one computer at home. My preference is to be able to use the resulting tool on almost any machine.

The approach I have in mind is:
- Define the initial geometry (i.e. pickup points, cg height, static equilibrium forces)
- Impose a lateral acceleration on the cg
- Assume that the lateral force at the contact patch is equal to k*F_z (just to get the solver working, then improve the tire model)
- Iteratively solve for the resulting equilibrium geometry and forces.

Sounds simple, huh? Any tips, tricks, or comments on the approach? I'm hoping to get it working by the end of the year.

 

[BillyShope]

You can verify your results...at least as far as roll stiffness distribution and effective roll center heights...by using the procedure described on Page 1 of my blog. This involves the use of essentially only a set of wheelscales.

http://home.earthlink.net/~whshope

 

[hutch325]

Thanks, Billy.

I take it there are no other comments? I should have time to work on it while the turkey cooks in a couple days.

 

[Fabrico]

What kind of vehicle is this? It can make a difference.