MODCHG

Subcase Information Entry

MODCHG – Data Selection

Description

The MODCHG command can be to remove and/or reactivate contact interfaces and/or elements for this subcase. It is used only for nonlinear analysis.

Format

MODCHG = option

Argument

Options

Description

option

< SID >

No default

SID: Set identification of a MODCHG bulk data entry.

1.	MODCHG bulk data entries will not be used unless selected in the Subcase Information section.

2.	For a fresh nonlinear analysis subcase (without any CNTNLSUB or with CNTNLSUB prescribed to be NO), a contact interface and a set of elements can be active or inactive depending on whether and how they are referenced by MODCHG.

3.	For a subsequent nonlinear analysis subcase (with CNTNLSUB prescribed to be YES or a subcase ID), a contact interface and a set of elements can be active or inactive depending on whether and how they are referenced by MODCHG and whether they are active or not in the preceding subcase.

Contact and/or Elements	Active/Inactive
Removed with MODCHG	Inactive
Added with MODCHG	Active
Others	Active, if active in the preceding subcase; Inactive, if inactive in the preceding subcase.