You can specify controls for the adaptive meshing and advection algorithms applied to an adaptive mesh domain. For more information, see “ALE adaptive meshing and remapping in Abaqus/Explicit,” Section 12.2.3 of the Abaqus Analysis User's Guide, and “ALE adaptive meshing and remapping in Abaqus/Standard,” Section 12.2.7 of the Abaqus Analysis User's Guide.
The following sections provide instructions for specifying ALE adaptive mesh controls:
You use the Edit ALE Adaptive Mesh Controls dialog box to customize various aspects of the adaptive meshing and advection algorithms applied to an adaptive mesh domain. For more information, see “ALE adaptive meshing and remapping in Abaqus/Standard,” Section 12.2.7 of the Abaqus Analysis User's Guide.
To specify controls for ALE adaptive meshing:
From the main menu bar, select Other
ALE Adaptive Mesh ControlsCreate.
A Create ALE Adaptive Mesh Controls dialog box appears.
In the dialog box, type a name for the ALE adaptive mesh controls, and click Continue.
The Edit ALE Adaptive Mesh Controls dialog box appears.
Click the arrow to the right of the Smoothing algorithm field, and select a method for calculating adaptive mesh smoothing:
Select Determined by analysis product to accept the default for the analysis product you are using (in this case, Abaqus/Standard).
Select Enhanced algorithm based on evolving geometry to use geometrically enhanced forms of the basic smoothing algorithms as a technique to mitigate distortion. These forms are heuristic and based on nodal locations only. Due to their heuristic nature, geometric enhancements may not always improve the mesh smoothing.
Select Conventional smoothing to use the conventional forms of the smoothing algorithms.
Calculation of the new mesh in Abaqus/Standard is based on some combination of two basic smoothing methods: original configuration projection smoothing and volume smoothing. You must specify the weighting factor for each method in the Volumetric and Original configuration projection fields. For more information, see “Combining smoothing methods” in “ALE adaptive meshing and remapping in Abaqus/Standard,” Section 12.2.7 of the Abaqus Analysis User's Guide.
In the Initial feature angle field, enter the initial geometric feature angle, 
, in degrees (
). This angle is used to detect geometric edges and corners. The default value is 
. Setting 
will ensure that no geometric edges or corners are detected or enforced.
For more information, see “Controlling the detection of geometric edges and corners” in “Defining ALE adaptive mesh domains in Abaqus/Standard,” Section 12.2.6 of the Abaqus Analysis User's Guide.
In the Transition feature angle field, enter the transition geometric feature angle, 
, in degrees (
). This angle is used to determine when geometric edges and corners should be deactivated to allow remeshing across them. The default value is 
. Setting 
will ensure that no geometric edges or corners are deactivated.
For more information, see “Controlling the activation and deactivation of geometric edges and corners” in “Defining ALE adaptive mesh domains in Abaqus/Standard,” Section 12.2.6 of the Abaqus Analysis User's Guide.
Click OK to save the named set of controls and to close the editor.
You use the Edit ALE Adaptive Mesh Controls dialog box to customize various aspects of the adaptive meshing and advection algorithms applied to an adaptive mesh domain. For more information, see “ALE adaptive meshing and remapping in Abaqus/Explicit,” Section 12.2.3 of the Abaqus Analysis User's Guide.
To specify controls for ALE adaptive meshing:
From the main menu bar, select OtherALE Adaptive Mesh ControlsCreate.
A Create ALE Adaptive Mesh Controls dialog box appears.
In the dialog box, type a name for the ALE adaptive mesh controls, and click Continue.
The Edit ALE Adaptive Mesh Controls dialog box appears.
Choose a mesh smoothing Priority:
Choose Improve aspect ratio to perform adaptive meshing that minimizes element distortion and improves element aspect ratios at the expense of diffusing initial mesh gradation. This objective is recommended for problems with moderate to large overall deformation. For more information, see “Specifying a uniform mesh smoothing objective” in “ALE adaptive meshing and remapping in Abaqus/Explicit,” Section 12.2.3 of the Abaqus Analysis User's Guide.
Choose Preserve initial mesh grading to perform adaptive meshing that attempts to preserve initial mesh gradation while reducing distortions as the analysis evolves. This objective is recommended only for adaptive mesh domains with reasonably structured graded meshes undergoing low to moderate overall deformation. For more information, see “Specifying a graded mesh smoothing objective” in “ALE adaptive meshing and remapping in Abaqus/Explicit,” Section 12.2.3 of the Abaqus Analysis User's Guide.
Click the arrow to the right of the Smoothing algorithm field, and select a method for calculating adaptive mesh smoothing:
Select Determined by analysis product to accept the default for the analysis product you are using (in this case, Abaqus/Explicit).
Select Enhanced algorithm based on evolving geometry to use geometrically enhanced forms of the basic smoothing algorithms as a technique to mitigate distortion.
Select Conventional smoothing to use the conventional forms of the smoothing algorithms.
Choose a Meshing predictor option:
Choose Current deformed position to perform adaptive meshing based on current nodal positions. This method is recommended for all Langrangian-like problems and for problems with very large distortions. For more information, see “Positioning nodes in Lagrangian domains” in “ALE adaptive meshing and remapping in Abaqus/Explicit,” Section 12.2.3 of the Abaqus Analysis User's Guide.
Choose Position from previous ALE adaptive mesh increment to perform adaptive meshing based on the positions of the nodes at the end of the previous adaptive mesh increment. This technique is recommended for Eulerian-like problems where material flow is significant compared to the overall deformation. For more information, see “Positioning nodes in Eulerian domains” in “ALE adaptive meshing and remapping in Abaqus/Explicit,” Section 12.2.3 of the Abaqus Analysis User's Guide.
In the Curvature refinement field, enter a value for the curvature refinement weight, 
. An appropriate value allows you to ensure that there is sufficient mesh refinement near highly curved boundaries. The default, 
, works well on a wide variety of problems. For more information, see “Solution-dependent meshing based on concave boundary curvature” in “ALE adaptive meshing and remapping in Abaqus/Explicit,” Section 12.2.3 of the Abaqus Analysis User's Guide.
Calculation of the new mesh in Abaqus/Explicit is based on some combination of three basic smoothing methods: volume smoothing, Laplacian smoothing, and equipotential smoothing. You must specify the weighting factor for each method in the Volumetric, Laplacian, and Equipotential fields. For more information, see “Mesh smoothing methods” in “ALE adaptive meshing and remapping in Abaqus/Explicit,” Section 12.2.3 of the Abaqus Analysis User's Guide.
In the Initial feature angle field, enter the initial geometric feature angle, , in degrees (). This angle is used to detect geometric edges and corners. The default value is . Setting will ensure that no geometric edges or corners are detected or enforced.
In the Transition feature angle field, enter the transition geometric feature angle, , in degrees (). This angle is used to determine when geometric edges and corners should be deactivated to allow remeshing across them. The default value is . Setting will ensure that no geometric edges or corners are deactivated.
In the Mesh constraint angle field, enter the mesh constraint angle, 
, in degrees (
). The default value is 
.
When adaptive mesh constraints are applied to nodes on Lagrangian or sliding boundary regions, the analysis will terminate if the angle between the normal to the boundary region and the direction of the prescribed constraint becomes less than . When adaptive mesh constraints are applied to nodes that are part of a Lagrangian or active geometric edge, the analysis will terminate if the angle between the prescribed constraint and the plane perpendicular to the edge becomes less than .
Choose an algorithm for remapping solution variables after adaptive meshing has been performed:
Choose First order to use a first order method based on donor cell differencing.
Choose Second order to use a second order method based on the work of Van Leer.
Choose a method for advecting momentum:
Choose Element center projection for the least expensive method.
Choose Half-index shift for a method that is more expensive computationally but which may demonstrate better dispersion properties.
Click OK to save the named set of controls and to close the editor.