Tuesday,
March 23, 1999, 12:15 p.m. in GWC Room 604
Florian Potra
Department of Mathematics, University of Maryland - Baltimore County
Modeling rigid-multi-body dynamics with contacts and friction
Abstract
The field of multi-body dynamics simulation is expected to have a
major impact on the design of complex mechanical systems, such as
robots and assembly line manipulators. Finding realistic models for
impact and friction is very important for accurate simulation. Using
the rigid body hypothesis substantially simplifies the model and
therefore reduces the complexity of the governing equations.
Unfortunately, it has been known for over a century that there are
examples of rigid multi-body systems with Coulomb friction which have
no mathematical solution in the classical sense. Various authors have
proposed different settings in which the rigid multi-body system
problem with Coulomb friction has a generalized solution either by
allowing for impulsive forces (i.e., a solution in the sense of
distributions) or by considering the equations of motion as
differential inclusions rather than differential equations. In our
talk we present a discrete model that has a computable solution under
general conditions and which is very well suited for simulating
multi-body systems with friction. A simulation package based on this
model is being now implemented at the University of Iowa and some
numerical results obtained with a preliminary version of that package
will illustrate the theory.
