Mechanical APDL Basic Analysis Guide - Ansys

The surfaces you create fall into three categories:
• A cross section you create based on the current working plane
• A closed surface represented by a sphere at the current working plane origin, with a user-specified radius.
• A cylindrical surface centered at the working plane origin, and extending infinitely in the positive and
negative Z directions
For SurfType = CPLANE, nRefine refers to the number of points that define the surface. If SurfType
= CPLANE, and nRefine = 0, the points reside where the cutting plane section cuts through the element.
Increasing nRefine to 1 will subdivide each surface facet into 4 subfacets, thus increasing the number of
points at which the results can be interpolated. nRefine can vary between 0 and 3. Increasing nRefine
can have significant impact on memory and speed of surface operations.
/EFACET operations will add to this refinement, and values greater than 1 can amplify the effect of nRefine.
An /EFACET setting greater than 1 divides the elements into subelements, and nRefine then refines the
facets of the subelements.
For SurfType = SPHERE, and INFC, nRefine is the number of divisions along a 90° arc of the sphere
(default is 90, Min = 10, Max = 90).
Each time you create a surface, the following predefined geometric items are computed and stored.
• GCX, GCY, GCZ - global Cartesian coordinates at each point on the surface.
• NORMX, NORMY, NORMZ - components of the unit normal at each point on the surface.
• DA - contributory area of each point.
These items are used to perform mathematical operations with surface data (for instance, DA is required to
calculate surface integrals). Once you create a surface, these quantities (using the predefined labels) are
available for all subsequent math operations.
Issue SUPL,SurfName to display your defined surface. A maximum of 100 surfaces can exist within one
model, and all operations (mapping results, math operations, etc.) will be carried out on all selected surfaces.
You can use the SUSEL command to change the selected surface set.
See the SUCR command for more information of creating surfaces.
Note
When you define a cylinder (INFC), it is terminated at the geometric limits of your model. Also,
any facet lying outside of those limits is discarded.
7.2.2.2. Mapping Results Data Onto a Surface
Once you define a surface, use the SUMAP command to map your data onto that surface. Nodal results
data in the active results coordinate system is interpolated onto the surface and operated on as a result set.
Your result sets can be made up of primary data (nodal DOF solution), derived data (stress, flux, gradients,
etc.), FLOTRAN nodal results, and other results values.
You define your mapped data in the SUMAP command by supplying a name for the result set, and then
specifying the type of data and the directional properties.
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7.2.2. Surface Operations
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