I am wondering what kind of floating frame of reference (FFR) ADAMS is actually using. In literature, three are common: (1) body attached FFR, (2) Tisserand Frame (= Mean Axis Frame) and (3) Buckens Frame (=Linearized Means Axis Frame).
Number (1) and (2) need additional constraint equations which would lead to additional Lagrange multiplicators. I cannot observe them when I go to “Model Verify” and look to the number of degrees of freedom.
Remaining option is (3), the Buckens frame. In general, the Buckens frame requires constraint equations as well. Just in the case when the FFR is located in the center of mass, the Buckens frame conditions are fulfilled automatically – at least partially and approximately. But, if this would be the strategy of ADAMS, I do not understand the availability of the invariants I2, I3 (and consequently I4 and I5).
I tried to figure out something about this issue in the manual and I browsed the entries in the “Flexible Body” discussion. I couldn’t find anything.
I am working on some theoretical questions concerning multi body dynamics and I would appreciate information’s on that issue.
Wolfgang
