NEW METHOD FOR CONSTRAINTS VIOLATION SUPPRESSION

The problem of constraints violation associated with numerical integra tion of dynamical equations of motion subject to constraints is dealt with. A new method for the suppression of constraints violation is pre sented. The method involves the definition of old constraints and of n ew constraints, the removal of the old constraints and the imposition of the new constraints, and the evaluation, after each integration ste p, of changes in the integration variables resulting from the removal- imposition process. The method is shown to be superior to the classica l Baumgarte's method for constraints violation suppression in three as pects. First, the constraint violation measure number, a quantity defi ned herein, is smaller. Second, the constraint violation measure numbe r stabilizes after the first integration step and does not degrade wit h time. Finally, the new method makes the process of trial and error, required by Baumgarte's method for the determination of integration co nstants, unnecessary. The method is discussed in connection with holon omic and simple nonholonomic constraints.