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vk.com/club152685050Rezoning | vk.com/id446425943

4.7.1.2.Remeshing Using a Generic New Mesh (2-D and 3-D)

4.7.1.3.Remeshing Using Manual Mesh Splitting (2-D and 3-D)

4.7.1.1. Remeshing Using a Program-Generated New Mesh (2-D)

This remeshing method requires the AREMESH and AMESH commands, as shown in Figure 4.1: Rezoning Using a Program-Generated New Mesh (p. 93). Remeshing using a program-generated mesh is available for 2-D analyses only.

The following topics are available if you intend to remesh with a program-generated mesh:

4.7.1.1.1.Creating an Area to Remesh

4.7.1.1.2.Using Nodes From the Old Mesh

4.7.1.1.3.Hints for Remeshing Multiple Regions

4.7.1.1.4.Generating a New Mesh

To study a sample problem, see Example: Rezoning Using a Program-Generated New Mesh (p. 124).

4.7.1.1.1. Creating an Area to Remesh

Based on the selected region, the AREMESH command creates an area to generate the new mesh. The program validates the selected region and creates an area on that region for the new mesh. The program maintains compatibility with neighboring regions, and nodes with applied loads and boundary conditions remain intact.

How the program creates the boundary lines affects the new mesh quality and mesh density on the area; therefore, specify AREMESH command options carefully. The boundary lines are based on the element edges on the boundary of the selected region, as follows:

Line combining (AREMESH,0) allows you to redistribute the new nodes on the boundary and provides more control over the new element size. New elements can be larger or smaller. If the boundary is highly curved, however, the new element edges may constitute a slightly different boundary.

If line segments are not combined (AREMESH,-1), the new boundary will match the old one. In this case, you cannot control the positions of old nodes on the boundary (which may result in an unacceptable new mesh), and elements on the boundary can only be the same size or smaller.

To maintain compatibility, the program does not combine line segments connected to elements outside the selected remeshing region (even if you specify line combining). Also, two segments are not combined if an old node is located between them and that node:

Has applied force or displacements, or

Is the starting and ending point of applied pressures, distributed displacements, or contact boundaries.

4.7.1.1.2. Using Nodes From the Old Mesh

It is best to avoid using nodes from the old mesh whenever possible. Retaining old nodes introduces more constraints when generating the new mesh and makes it more difficult to create a new mesh of better quality.

If necessary, you can retain some old nodes on the boundaries of the selected region to use on the new mesh. To do so, select the nodes that you want to keep and group them into a nodal component named _ndnocmb_rzn (CM,_ndnocmb_rzn,NODE) before issuing the AREMESH command.

 

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