Hmmmm ... I think the item not addressed are the fundamentals of tire mechanics. A tire can generate a longitudinal force greater than it's vertical force (Newton is frowning) irrespective of weight transfer and aero. As I remember, one of the members of this group is a tire guy and could...
Another source for inertias is the NHTSA site ... measured and derived data.
http://www-nrd.nhtsa.dot.gov/vrtc/ca/nhtsa_inertia_database_english.pdf
Kevin
Hmmmm ... There are two kinds of coil spring spacers. Spacers that go between coils and those that are placed at the ends of the coil pack. You website suggest the later.
As bhart pointed out, the pre-load is determined by the difference between the free height of the spring and it's...
No answers - OK - I'll give this a go with the caveat that I'm not an elastomers engineer and whole books are dedicated to understanding just parts of this.
For constant slip and camber angles, the coefficient of friction does decrease with increasing load. You are right that there are two...
In order:
1) Generating a full 3D model with toe curves is something I have looked at. I do not have the time to generate it from scratch. However, I have an existing Fortran program that we use for this. I've been looking into front & back ending the batch Fortran program with .NET for web...
Thanks for the suggestions - those can be incorporated ... knowing the gain is clearly helpful. However, there's no substitute for a curve (which I suspect you are alluding to). Having looked at the referenced program - it's doable. Do I have the time to do it ... ?
Kevin
Greg,
Sorry, the answer to question #1 is that it's real tire data from a flat bed tester.
As for a wish list on the roll center app - let me know and I'll see what I can put in the next version.
Kevin
Joest - I've given everything I have. If someone wants to shoot me data, I'll gen the coefficients.
Greg - I'm running Mozila and looks OK (marginal) ... I'll try to fix it - aaahhhh the benefits of .NOT
Kevin
Greg has published a simple roll center calulator using Excel, but there seem to be enough questions that I generated a web based .NET application to calc RC's for SLA & MacPherson. Ya, it's static, simple but may be of use to someone.
Tire data seems to be limited. So, I generated a web based...
The problem is that the stiffness of the steering system has changed. This could be from steering gear wear (even adjusting preload may not fix this) or worn rag joints (if so equiped), etc. The root of the problem lies in the natural frequency of the system as designed. Since freq = sqrt(k/m)...
In lieu of any standards, I would think that solenoid sizing would be the primary design consideration ($, packaging, throw, sticktion, etc) and determine the spring required.
Kevin
Greg,
I agree with your point about roll center height being bracketed by traditional designs (packaging constraits, etc) - which minimize vehicle performance variability via RCH concept.
Except for development engineers, lay folks and even a lot of auto enthusiast didn't really notice...
Greg,
You said it in your first post, and you said it in this last post - and I agree - cars usually do not roll around the roll centers. The roll centers are defined by the suspension geometry (and hence the forces by Kennedy's theorem). Therefore, these are, by definition, force based roll...
