I'm using Adams/Adams car on a multibody model of motorcycle which has PAC MC tire model. Can I modify the PAC MC Tire model in order to have a lateral and radial stiffness instead of a vertical stiffness ?
I'm using Adams/Adams car on a multibody model of motorcycle which has PAC MC tire model. Can I modify the PAC MC Tire model in order to have a lateral and radial stiffness instead of a vertical stiffness ?
To my knowledge there aren't simple variables that can be defined like the VERTICAL_STIFFNESS variable. However, there may be a way to get there by modifying some of the coefficients within the property file. There is a lot of information in the help documentation. I suggest looking at:
Adams Car Package > Adams Tire > Tire Models > Using the PAC MC Tire Model
Thanks Alex, I have already seen the Adams tire help and seems to be no properties for what I would like to do. There are some coefficients that act on the vertical force depending on camber angle, but are not what I'm looking for. Moreover, I think I can't use models other than PAC MC because of large camber angles.
I am not an expert in using Adams, so I am searching for some pratical hints on how I could achieve my target, i.e to insert a radial spring (for radial compression of tire) and an lateral spring (for axial compression of tire), like the model below:
Pacijeka tires are point-follower models; i.e. the whole behavoir is condensed into equations that return 6 force/torque directions relative to that point. They're usually only suitable for handling analysis.
I need a tire model, because I want to realize a linear analysis during a full vechile simulation (straight and cornering), to obtain eigenvalues and eigenvectors.
I will study the FTIRE model and understand if it can be useful for my appliance.
260089 (?), can you let use know more about your affiliation? Depending on what kind of project you are working on and for whom, maybe you are eligible for an FTire license at reduced cost. Please contact sales@cosin.eu.
I think FTire *is* the way to go for your application.
Twenty+ years ago I had a miserable experience attempting eigenvalue/vector methods with motorcycle models in ADAMS/View that included relaxation length. Six years ago I replicated the miserable experience with VI-Motorcycle.
I went back to View and wrote a time domain test that was equivalent to the "hip flick" I perform when testing weave damping on real motorcycles. I wrote some postprocessing in Octave (which is free) to fit a damped sine wave to a portion of the roll response history and extracted frequency and damping ratios from that.
It also works for wobble/flutter damping and isn't contingent on any particular model construction or toolkit. It further has the advantage of being the method that is used for postprocessing the test data from a real motorcycle, which means you are correlating like for like.
You can administer the hip flick in any condition you like - straight line, mid corner, etc. I produced some "root locus" plots that were demonstrably similar in character to all Robin Sharp's work so I ended up pretty comfortable with it.
