Mapdl.nlgeom(key='', **kwargs)[source]#

Includes large-deflection effects in a static or full transient

APDL Command: NLGEOM analysis.


Large-deflection key:

OFF - Ignores large-deflection effects (that is, a small-deflection analysis is

specified). This option is the default.

ON - Includes large-deflection (large rotation) effects or large strain effects,

according to the element type.


Large-deflection effects are categorized as either large deflection (or large rotation) or large strain, depending on the element type. These are listed (if available) under Special Features in the input data table for each element in the Element Reference. When large deflection effects are included (NLGEOM,ON), stress stiffening effects are also included automatically.

If used during the solution (/SOLU), this command is valid only within the first load step.

In a large-deflection analysis, pressure loads behave differently than other load types. For more information, see Load Direction in a Large- Deflection Analysis.

The gyroscopic matrix (that occurs due to rotational angular velocity) does not support large-deflection effects. The theoretical formulations for the gyroscopic matrix support small deflection (linear formulation) only.

When large-deflection effects are included in a substructure or CMS transient analysis use pass, the OUTRES command ignores DSUBres = ALL.

This command is also valid in PREP7.

In ANSYS Professional NLT, large deflection effects should not be turned on if 2-D solid (PLANEn) or 3-D solid (SOLIDn) elements are defined. ANSYS Professional NLS supports NLGEOM,ON for plane and solid elements.