Warning: Using values larger than the default values for hourglass control can produce excessively stiff response. Hourglassing that occurs with the default hourglass control parameters is usually an indication that the mesh is too coarse. Therefore, it is generally better to refine the mesh than to add stronger hourglass control.
This option is used to choose a nondefault hourglass control approach for reduced-integration elements or to scale the default coefficients used in the hourglass control. In ABAQUS/Explicit it is also used to select a nondefault kinematic formulation for 8-node brick elements, to choose the second-order accurate formulation for solids and shells, to activate distortion control for solid elements, to scale the linear and quadratic bulk viscosities, to specify whether elements must be deleted when they are completely damaged, or to specify a value of the scalar degradation parameter at or above which elements are assumed to be completely damaged. It is used in conjunction with the *MEMBRANE SECTION, *SHELL GENERAL SECTION, *SHELL SECTION, and/or *SOLID SECTION options. It can be used with *BEAM SECTION and *BEAM GENERAL SECTION to scale the linear and bulk viscosities. It can also be used with the *COHESIVE SECTION option to specify whether elements must be deleted when they are completely damaged, to specify a value of the scalar degradation parameter at or above which elements are assumed to be completely damaged, or, in ABAQUS/Standard, to specify the viscosity coefficient that controls the viscous regularization.
Products: ABAQUS/Standard ABAQUS/Explicit
Type: Model data
Level: Model
Set this parameter equal to the name that will be used to identify the section control definition. All section control names in the same input file must be unique.
This parameter applies only to ABAQUS/Explicit analyses.
Set DISTORTION CONTROL=YES to activate a constraint that acts to prevent negative element volumes or other excessive distortion for crushable materials. This is the default value for elements with hyperelastic or hyperfoam materials. The DISTORTION CONTROL parameter is not relevant for linear kinematics and cannot prevent elements from being distorted due to temporal instabilities, hourglass instabilities, or physically unrealistic deformation.
Set DISTORTION CONTROL=NO to deactivate a constraint that acts to prevent negative element volumes or other excessive distortion for crushable materials. This value is the default except for elements with hyperelastic or hyperfoam materials.
This parameter applies to ABAQUS/Explicit analyses and only to cohesive elements in ABAQUS/Standard analyses.
Set ELEMENT DELETION=YES to allow element deletion when the element has completely damaged. This value is the default for all elements with a damage evolution model.
Set ELEMENT DELETION=NO to allow fully damaged elements to remain in the computations. The element retains a residual stiffness given by the specified value of MAX DEGRADATION. In addition, elements with three-dimensional stress states (including generalized plane strain elements) can sustain hydrostatic compressive stresses, and elements with one-dimensional stress states can sustain compressive stresses. This value is not available for beam elements.
Set HOURGLASS=COMBINED to define the viscous-stiffness form of hourglass control for solid and membrane elements with reduced integration in ABAQUS/Explicit.
Set HOURGLASS=ENHANCED (default for elements with hyperelastic and hyperfoam materials in ABAQUS/Standard and ABAQUS/Explicit) to define hourglass control that is based on the assumed enhanced strain method for solid, membrane, and finite-strain shell elements with reduced integration in ABAQUS/Standard and ABAQUS/Explicit. Any data given on the data line will be ignored for this case.
Set HOURGLASS=RELAX STIFFNESS (default for ABAQUS/Explicit, except for elements with hyperelastic and hyperfoam materials) to use the integral viscoelastic form of hourglass control for all elements with reduced integration in ABAQUS/Explicit.
Set HOURGLASS=STIFFNESS (default for ABAQUS/Standard, except for elements with hyperelastic and hyperfoam materials) to define hourglass control that is strictly elastic for all elements with reduced integration in ABAQUS/Standard and ABAQUS/Explicit.
Set HOURGLASS=VISCOUS to define the hourglass damping used to control the hourglass modes for solid and membrane elements with reduced integration in ABAQUS/Explicit.
Include this parameter to change the kinematic formulation for 8-node brick elements only.
Set KINEMATIC SPLIT=AVERAGE STRAIN (default in ABAQUS/Explicit) to use the uniform strain formulation and the hourglass shape vectors in the hourglass control. This is the only option available for ABAQUS/Standard.
Set KINEMATIC SPLIT=CENTROID to use the centroid strain formulation and the hourglass base vectors in the hourglass control in ABAQUS/Explicit.
Set KINEMATIC SPLIT=ORTHOGONAL to use the centroid strain formulation and the hourglass shape vectors in the hourglass control in ABAQUS/Explicit.
If SECOND ORDER ACCURACY=YES, the KINEMATIC SPLIT parameter will be reset to AVERAGE STRAIN in ABAQUS/Explicit.
This parameter applies only to ABAQUS/Explicit analyses and is valid only when the DISTORTION CONTROL parameter is used.
Set this parameter equal to 
(
) to define the length ratio when using distortion control for crushable materials. The default value is 
.
This parameter applies to ABAQUS/Explicit analyses and only to cohesive elements in ABAQUS/Standard analyses.
Set this parameter equal to the value of the damage variable at or above which a material point will be assumed to be completely damaged. This parameter also determines the amount of residual stiffness that will be retained by elements for which the ELEMENT DELETION parameter is set to NO. For elements other than cohesive elements the default value is 1.0 if the element is deleted from the mesh and 0.99 otherwise. For cohesive elements the default value is always 1.0.
Set SECOND ORDER ACCURACY=YES to use a second-order accurate formulation for solid or shell elements suitable for problems undergoing a large number of revolutions (> 5) in ABAQUS/Explicit. This is the only option available for ABAQUS/Standard.
Set SECOND ORDER ACCURACY=NO (default in ABAQUS/Explicit) to use the first-order accurate solid or shell elements in ABAQUS/Explicit.
The SECOND ORDER ACCURACY parameter is not relevant for linear kinematics.
This parameter applies only to ABAQUS/Standard analyses and only for cohesive elements.
Set this parameter equal to the value of the viscosity coefficient that will be used in the viscous regularization scheme for cohesive elements. The default value is 0.0.
This parameter applies only to ABAQUS/Explicit analyses.
Set this parameter equal to 
(
) to scale the contributions from the constant hourglass stiffness term and the hourglass damping term to the hourglass control formulation. Setting 
or 
corresponds to pure constant stiffness hourglass control and pure damping hourglass control, respectively. The default is 
. This option is used only for solid and membrane elements when the HOURGLASS parameter is set equal to COMBINED.
First (and only) line:
Scaling factor, 
, for the hourglass stiffness, for use with displacement degrees of freedom. If this value is left blank, ABAQUS will use the default value of 1.0. The suggested range for the value of is between 0.2 and 3.0.
Scaling factor, 
, for the hourglass stiffness, for use with rotational degrees of freedom in shell elements. If this value is left blank, ABAQUS will use the default value of 1.0. The suggested range for the value of is between 0.2 and 3.0.
Scaling factor, 
, for the hourglass stiffness for use with the out-of-plane displacement degree of freedom in small-strain shell elements in ABAQUS/Explicit. If this value is left blank, ABAQUS/Explicit will use the default value of 1.0. The suggested range for the value of is between 0.2 and 3.0. This scaling factor is not relevant for ABAQUS/Standard.
Scaling factor for the linear bulk viscosity in ABAQUS/Explicit. If this value is left blank, ABAQUS/Explicit will use the default value of 1.0. The suggested range for the value is between 0.0 and 1.0. This scaling factor is not relevant for ABAQUS/Standard.
Scaling factor for the quadratic bulk viscosity in ABAQUS/Explicit. If this value is left blank, ABAQUS/Explicit will use the default value of 1.0. The suggested range for the value is between 0.0 and 1.0. This scaling factor is not relevant for ABAQUS/Standard.