Area Object Dividing and Meshing

CSiBridge allows area objects to be divided into smaller objects in the object-based model, and meshed into elements in the analysis model. Dividing the object is accomplished using the Advanced > Edit > Areas > Divide Areas command. Meshing an area object is accomplished using the Advanced > Assign > Areas > Automatic Area Mesh command.

The options for dividing and meshing a selected area object add points that lie on the edges of the object, use straight lines that cross the edges of the object, or specify points that must lie within the selected area object. These basic types of area object dividing/meshing are described in this topic, as follows:

Dividing/Meshing By Adding Points On the Edges of An Area Object

Note:  Dividing/meshing by adding points on edges of area objects is applicable to triangles and quadrilaterals only.

Consider the following figure that shows an area object defined by points 1 through 4 and edges A through D. Points 5 and 6 lie on edge A, point 7 is on edge B, and point 8 is on edge C. Edge D has no points.

 

Dividing/meshing based on points on the edges of an area objects adds an equal numbers of points on opposite edges of the area object. Thus, in the above example, the program adds point 9 to edge C and point 10 to edge D, as shown in the following figure.

Edges A and C have two points each and edges B and D have one point each. Point 9 has been added to edge C at a relative distance from point 4 that is similar to the distance along edge A of point 5 from point 1. Point 10 has been added to edge D at a relative distance from point 1 that is similar to the distance along edge B of point 7 from point 2.

With an equal number of points defined on opposite edges of the area object, the program divides/meshes the object by drawing lines between the points on the opposite edges, as shown in the following figure. In this example, the dividing/meshing breaks the original area object into six area objects.

Adding points to the edges of area objects can be accomplished by specifying the number of objects/elements to be created, the size of the objects/elements to be created, or direct determination of intersections of specified lines and edges. The specific options are described in the Advanced > Edit > Areas > Divide Areas and Advanced > Assign > Areas > Automatic Area Mesh topics. The options can be generally described as follows:

Cookie Cutter Dividing/Meshing Based on Lines Crossing the Area Object

Consider the following figure that shows an area object defined by points 1 through 4 and edges A through D. Also shown are Line 1, Line 2 and Line 3, which lie in the plane of the area object.

 

Cookie cutter meshing uses the specified lines that cross the edge(s) of the selected area object, as shown in the following figure.

 

As needed, the program adds points along the edge opposite the line/edge intersection point to generate the divided objects/meshed elements. The following figure shows how in this example the program uses the lines and projected points to cookie cut divide/mesh the original area object into six objects/elements.

Cookie cut dividing/meshing based on lines crossing the selected area object can be accomplished using a straight line object or a selected point. The specific options are described in the Advanced > Edit > Areas > Divide Areas and Advanced > Assign > Areas > Automatic Area Mesh  topics. The options can be generally described as follows:

General Divide/Mesh

The general divide/mesh option divides/meshes the area objects into quadrilateral elements based on three parameters:

The maximum object/element dimension is always specified.  The specification of points and lines inside of the area object is optional. Consider the area object shown in the following figure that has the point labeled A inside it.

 

The figure below shows the result of general dividing/meshing of the area object considering point A and specifying a maximum object/element dimension that is approximately one quarter of the length of the sides of the area object.

The specific options are described in the Advanced > Edit > Areas > Divide Areas and Advanced > Assign > Areas > Automatic Area Mesh topics.