VisualAnalysis Tutorials: Area Meshing
Modeling a Concrete Tank with a Divider Wall using the automatic meshing capabilities available for areas. This feature allows you to create an area (a general purpose polygonal shape with or without holes) and then automatically mesh the area with plate elements. The plate elements generated will be connected to any model objects (beams, plates, springs, nodes, other areas, etc.) which happen to intersect the area being meshed. To demonstrate this we will show how easy it is to model a concrete tank with a partial height divider wall. For this tutorial we'll assume the tank is 50' wide and 100' long and 15' high. We'll also assume the divider wall is 10' high and lies half way along the 100' side.
To start off we open VisualAnalysis and create a new Space Frame because of the 3-D nature of this structure:
Because we want to be able to draw areas where the walls are located we can begin by entering some control points for the tank. Another feature in VA is Multiple Node generation in the Create Tab of the Project Manger. This feature is located under the Quick Items category and is shown below. We utilize a spreadsheet similar to Excel. Formulas and copy/paste allow you to quickly enter coordinates. Shown below are the 12 nodes entered to create our area corner points.
After closing the dialog above, the following is displayed in the Model View.
The next step is to create the 5 walls and base of the tank as area objects. To turn on area drawing select the toolbar button circled below:
We now click on the first corner of a wall area then click on the remaining 3 corners to generate the area. By clicking back on the first corner, the area drawing is ended and the area is created. After doing this for all six areas my model view now looks like this:
The final step is to select all the areas by holding down the shift button then clicking on any area. We can now turn on automatic meshing for all the areas by clicking on the "Auto. Generate" item in the Modify Tab of the Project manager. This is shown below:
The areas will be meshed automatically. The resulting mesh is shown below.
Inspection of the model shows that at the intersections of the areas the plate elements join at common nodes. This generates the continuity which exists with walls and slabs in tanks. After entering area loads for interior fluids and applying springs on the base slab an analysis is performed. Sample results for analysis are shown below.
In summary, VisualAnalysis has enhanced the use of area objects in modeling structures. The areas can be quickly drawn though control points created using powerful spreadsheet entry. Once areas are created they are meshed into plate elements automatically creating the necessary continuity at intersections. The entry of loading can be done by applying loads directly to the area objects. Spring supports are easily generated for soil support. The image below shows the bearing pressure output. This is also a new feature in VisualAnalysis and be useful with structures bearing on soil foundations.