Adams Basic Package > Adams View > View Command Language > executive_control > executive_control set dynamics_parameters coord_partitioning_parameters

executive_control set dynamics_parameters coord_partitioning_parameters

The COORD_PARTITIONING_PARAMETERS command allows you to control the coordinate partitioning algorithm for the Adams-Bashforth-Moulton integrator. This command affects the coordinate partitioning as well as the iterative solutions for the dependent displacements and the accelerations and Lagrange multipliers.

Description:

Parameter	Value Type	Description
model_name	An existing model	Specifies the model to be modified. You use this parameter to identify the existing model to be affected with this command.
dd_relative_error	Real	Specifies the relative error tolerance for the iterative solution of the displacements of the dependent coordinates. The relative error for the displacements will be bounded by a minimum of DD_RELATIVE_ERROR and the integration error tolerance.
dd_absolute_error	Real	Specifies the absolute error tolerance for the iterative solution of the displacements of the dependent coordinates. The absolute error for the displacements will be bounded by a minimum of dd_absolute_error and 1/100-th of the integration error tolerance.
dd_maximum_iterations	Integer	Specifies the maximum number of iterations allowed for the modified Newton-Raphson algorithm to converge to the displacements for the dependent coordinates.
dd_pattern_for_jacobian	Yes/No	Indicates the pattern of yes’s and no’s for reevaluating the Jacobian matrix during the modified Newton-Raphson iterative solution for the displacements of the dependent coordinates.
repartition_threshold	Real	Allows some control over the re-partitioning of coordinates into independent and dependent coordinates.
al_relative_error	Real	Specifies the relative error tolerance for the iterative solution of the accelerations and the Lagrange multipliers (i.e. constraint forces).
al_absolute_error	Real	Specifies the absolute error tolerance for the iterative solution of the accelerations and the Lagrange multipliers (i.e. constraint forces).
al_maximum_iterations	Integer	Specifies the maximum number of iterations allowed for the modified Newton-Raphson algorithm to converge to the accelerations and the Lagrange multipliers.
al_pattern_for_jacobian	Yes/No	Indicates the pattern of yes's and no's for reevaluating the Jacobian matrix during the modified Newton-Raphson iterative solution for the accelerations and the Lagrange multipliers.
scaling	Yes/No	No action will be taken if this parameter is not specified.
scale_factor	Real	Allows you to specify the amount to scale the geometry that is read in from a Wavefront .obj file. The geometry will be scaled uniformly in the x, y, and z directions.
watch_partitioning_perf	ERROR_IN_ITERATION, NO_ERROR_IN_ITERATION, FAILURE_IN_ITERATION, NO_FAILURE_IN_ITERATION, CONDITION, NO_CONDITION, REPARTITION, NO_REPARTITION, DOF, NO_DOF, ALL, NONE	Provides the user with a means for observing the progress of the simulation by causing Adams to write information about the performance of coordinate partitioning calculations onto the screen.

Extended Definition:

1. You may identify a model by typing its name or by picking it from the screen.

If the model is not visible on the screen, you must type the name. You may also find it convenient to type the name even if the model is displayed.

You must separate multiple model names by commas.

If the model is visible in one of your views, you may identify it by picking on any of the graphics associated with it.

You need not separate multiple model picks by commas.

2. In general, for efficiency reasons, the coordinates are re-partitioned whenever:

■A matrix inverse condition number gets too small

■The displacment iterations do not converge

■A part rotation occurs

■A matrix becomes numerically singular, or

■ The unit energy ratio is less than its original value times the value of REPARTITION_THRESHOLD.

3. The relative error will be bounded by a minimum of AL_RELATIVE_ERROR and one tenth of the integration error tolerance.

4. The absolute error will be bounded by a minimum of AL_ABSOLUTE_ERROR and one tenth of the integration error tolerance.

5. The WATCH_PARTITIONING_PERF only affects diagnostics, not results.

ERROR_IN_ITERATION: The value of the error and the component of the state vector, contributing the most to the size of the error after every iteration of the algorithm of the dependent displacements and for the accelerations and the constraint forces.

FAILURE_IN_ITERATION: The value of the error and the component of the state vector, contributing the most to the size of the error when the algorithm for the dependent displacements and for the accelerations and the constraint forces fails to converge.

CONDITION: An estimate of the condition number of the Jacobian matrix for the corrector algorithm each time it is reevaluated.

REPARTITION: An indication that the current choice for the independent coordinates is no longer acceptable and the coordinates will be re-partitioned.

DOF: A list of the degrees-of-freedom (i.e. the independent coordinates) each time the partitioning is done.

ALL: All options are on.

NONE: All options are off.