ADAMS For Kinematics

[Ballzac]

I was just wondering if anyone has used ADAMS to check their kinematics. When I put the same geometry into ADAMS (using the FSAE template and goodyear tire data) and Racing By The Numbers (specialized suspension program), I get very different results. The only simulations i did in ADAMS were vertical wheel travel and roll&vertical force, so the kinematics should not be affected by any forces, because...its kinematics?? Has anyone had similar troubles? Could the tires be the culprit (there's a big difference, especially in lateral roll center migration in roll).

Thanks

[Ballzac]

I was just wondering if anyone has used ADAMS to check their kinematics. When I put the same geometry into ADAMS (using the FSAE template and goodyear tire data) and Racing By The Numbers (specialized suspension program), I get very different results. The only simulations i did in ADAMS were vertical wheel travel and roll&vertical force, so the kinematics should not be affected by any forces, because...its kinematics?? Has anyone had similar troubles? Could the tires be the culprit (there's a big difference, especially in lateral roll center migration in roll).

Thanks

[Marc Jaxa-Rozen]

ADAMS uses force vector intersections to find the RC heights instead of the classic instant center method, so yes, it's normal for the results to differ, especially for lateral migration like you've noted.

[ben]

The kinematic roll centre is a linear assumption used to make analysis easier. ADAMS uses forces and moments as pointed out by Marc.

Whether or not the complexity of ADAMS is justified for simple kinematics or not and whether the standard results calculated are relevant is an entirely different matter however.

Ben