On the unique solvability of a direct dynamics problem for mechanisms with redundant constraints and Coulomb friction in joints
Janusz Frączek , Marek Wojtyra
AbstractThe uniqueness of simulated motion of an overconstrained rigid body mechanism with joint friction is studied. The investigated issue originates in the problem of joint reactions solvability. It is known that in case of redundant constraints existence the constraint reaction forces cannot be — in general — uniquely determined. It can be proved, however, that — under certain conditions — selected reactions can be specified uniquely. Analytical and numerical methods for reactions solvability analysis are available. It is shown in this paper that indeterminacy of normal reactions results in indeterminacy of friction forces, and moreover, non-uniqueness of friction forces results in non-uniqueness of simulated motion. A method of finding these joints, for which friction forces are unique, is presented. It is also proved that if only uniquely solvable friction effects are introduced, then simulated motion of the mechanism is unique, otherwise it is not. Finally, examples of dynamic analysis of overconstrained mechanisms with joint friction are presented; unique and non-unique results are obtained.
|Journal series||Mechanism and Machine Theory, ISSN 0094-114X, (A 35 pkt)|
|Publication size in sheets||1.1|
|Keywords in English||Coulomb friction, Dependent constraints, Direct dynamics, Joint reactions, Multibody system|
|ASJC Classification||; ; ;|
|Publication indicators||= 30; = 47; : 2014 = 2.951; : 2011 = 1.366 (2) - 2011=1.54 (5)|
|Citation count*||57 (2020-01-07)|
* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.