4.1. CSOPT Command Definition

Specifies solution options for a Mechanical APDL LS-DYNA co-simulation analysis.

CSOPT, --,Option, Value1, Value2, Value3, Value4

--

Unused field.

Option

Mechanical APDL LS-DYNA co-simulation analysis option. The semantic labels for Value1, Value2, Value3, and Value4 as well as their descriptions and default/range values depend on the option setting. See the command specifications for each option for details. Possible Option settings are:

CNVG

Specify co-simulation interface coupling convergence criteria. See Command Specification for Option = CVNG.

CNVT

Set convergence values when interface convergence checking is enabled.

This option is valid only when the command CSOPT,,CVNG,ON is issued. See Command Specification for Option = CNVT

NEQIT

Specifies the maximum number of equilibrium iterations when interface convergence checking is enabled.

This option is valid only when the command CSOPT,,CVNG,ON is issued. See Command Specification for Option = NEQIT

TIME

Specifies the total co-simulation run time. Required only for multiple-load steps analysis. See Command Specification for Option = TIME

Command Specification for Option = CVNG

CSOPT, CVNG, Value1

Table 4.1: Semantic labels and definitions of Value1 for Option = CVNG

Value Label and description
Value1ConvCheckFlag

FSI interface coupling convergence checking flag

Enabling the interface coupling convergence checking flag enhances the stability of the FSI coupling and improves solution accuracy. This is particularly true for transient analyses, when intermediate results are required. However, running with ConvCheckFlag = ON typically runs longer than when the flag is turned off.

Possible ConvCheckFlag settings are:

ON - Enable FSI interface coupling convergence checking

OFF - Turn off FSI interface coupling convergence checking


Command Specification for Option = CNVT

CSOPT, CNVT, Value1,Value2,Value3,Value4

Table 4.2: Semantic labels and definitions of Value1, Value2, Value3, and Value4 for Option = CNVT

Value Label and description
Value1Label

Convergence checking labels.

Possible Label settings are:
U

Displacements (Default)

F

Forces

Value2Value

Calculated reference value for the specified convergence label.

This is a program-calculated reference. Do not enter a value.

Value3Toler

Tolerance value used for the specified convergence label.

The Toler setting depends on Label specification as follows:
For Label = U

0.05 (5%) is the default value.

If you choose to specify a Toler value, it must be greater than zero and less than 1.

For Label = F

Inactive

Value4Norm

Specified norm selection.

Possible Norm settings are:
0

Infinite norm (default for Label = U).

1

L1 norm (check absolute value sum).

2

L2 norm (default for Label = F).


Command Specification for Option = NEQIT

CSOPT, NEQIT, Value1

Table 4.3: Semantic labels and definitions of Value1 for Option = NEQIT

Value Label and description
Value1MaxIter

Maximum number of equilibrium iterations allowed for each interface coupling substep.

Default: 15


Command Specification for Option = TIME

CSOPT, TIME, Value1

Table 4.4: Semantic labels and definitions of Value1 for Option = TIME

Value Label and description
Value1TotalTime

Total co-simulation time.

Only required for co-simulation analysis with multiple load steps.

TotalTime is the total time for all load steps.