*HOURGLASS STIFFNESS

Specify nondefault hourglass stiffness.

This option is relevant for first-order, reduced-integration elements; second-order, reduced-integration element types M3D9R, S8R5, and S9R5; and modified tetrahedral and triangular elements. It can also be used to define an hourglass scaling factor for the stiffness associated with the drill degree of freedom (rotation about the surface normal) in shell elements and to modify the hourglass stiffness factor for the pressure Lagrange multiplier degrees of freedom for C3D4H elements.

The HOURGLASS STIFFNESS option can be used only in conjunction with the MEMBRANE SECTION option, the SOLID SECTION option, the SHELL SECTION option, or the SHELL GENERAL SECTION option. The hourglass control defined with this option affects only those elements whose section properties are defined by the immediately preceding section option.

Related Topics
*MEMBRANE SECTION
*SHELL GENERAL SECTION
*SHELL SECTION
*SOLID SECTION
In Other Guides
Section controls

ProductsAbaqus/StandardAbaqus/CAE

TypeModel data

LevelPartPart instance

Abaqus/CAEMesh module

There are no parameters associated with this option.

 

Data line to define a nondefault hourglass stiffness

First (and only) line

  1. Hourglass control stiffness parameter (rF⁢G) for use with membrane and solid elements and for membrane hourglass mode control in shells. Units are stress (FL−2). If this value is left blank or entered as zero, Abaqus/Standard will use the default value.

  2. Hourglass control stiffness parameter (rF⁢K) for use with element type C3D4H. Units of this parameter depend on the material property assigned to the element. For nearly incompressible elastomers (HYPERELASTIC) and elastometric foams (HYPERFOAM) the units are stress (FL−2 ); for all other remaining materials, including fully incompressible elastomers, the units are stress compliance (F−1L2). If this value is left blank or entered as zero, Abaqus/Standard will use the default value.

  3. Hourglass control stiffness parameter (rθ⁢G) for bending hourglass mode control in shells. Units are stress (FL−2). If this value is left blank or entered as zero, Abaqus/Standard will use the default value.

  4. Factor by which the default stiffness for rotation about the shell surface normal is to be scaled (for shell nodes where six degrees of freedom are active). If this value is not entered or is entered as zero, Abaqus/Standard will use the default value.