VisualAnalysis has the ability to import and export .dxf  and .dwg CAD files. This drawing format typically contains basic geometry and connectivity information only, not an entire structural model. VisualAnalysis can do only so much with this format! DXF transfers will not support many of the features or properties of your models, but can help you save time in setting up complex models or in getting drawings started after creating a model in VisualAnalysis. 

Disclaimer

Because the DWG and DXF^™ formats are controlled by Autodesk^® Inc., and not IES, Inc., it is not possible to read all DXF files, or to output files to specific format requirements, and these formats may change after our tools have been tested!  CAD systems often use Z as the vertical direction, where VisualAnalysis prefers Y (though it functions with any axis vertical--set it in Project Settings), so you may wish to swap coordinates when importing or exporting.

CAD files are "dumb" collections of drawing entities--they do not contain a structural model! VisualAnalysis cannot always guess the intention of these lines or other entities and may require your assistance. Before importing your DXF file, check to make sure that the lines connect nicely (don't overlap), that coordinates are reasonable and near the global origin. For best results, split arcs and circles in to lines or poly-lines where they will cross members or nodes in your final model. You may need to import more than once, experimenting with settings or adjusting the CAD drawing slightly before it imports properly. Even then you may need to work with the project after importing to make a good model out of the data.

Import a File

Use File | Import | DXF File to read a drawing into the current project. You can also use File | Open and select DXF files to start a new project from a DXF file. This is a good way to create a model with complex geometry or to save work when a drawing is available before you begin. There are a number of options when importing from DXF files.

Layers: DXF files may contain lots of non-structural noise, be sure to include only the layers you want to import.

Select items to Import: This allows you to selectively import entities from the file while ignoring others. You can also define basic default properties to items (like member shapes and materials) before importing.

Swap Y and Z coordinates: VisualAnalysis uses Y as the vertical axis by default, while most CAD programs use Z. You can perform this translation automatically. The default is to swap the coordinates.

Units: Select the units that were used in the DXF file.

Scale Factor: You can scale the dimensions of the DXF model up or down by a constant factor. Every nodal coordinate position in the DXF file will be multiplied by the scale factor before it is displayed in VisualAnalysis.

Entities Imported:

• POINTS become nodes
• LINES, POLYLINES, CIRCLES, or ARCS become members
• SOLID or 3DFACE become a plate element

Export a File

To save a model as a CAD drawing use File | Export to DXF. There are a number of options in the Export to DXF dialog box.

Swap Y and Z coordinates: VisualAnalysis uses Y as the vertical axis by default, while most CAD programs use Z. You can perform this translation automatically. The default is to swap the coordinates.

Units in DXF: Select the units to display information in the DXF file. For the maximum precision, you may want to use a "small" unit like inches or millimeters.

Scale factor: You can scale the dimensions of the model up or down by a constant factor. Every nodal coordinate position in VisualAnalysis will be multiplied by the scale factor before it is written to the DXF file.

Selected items only: Selecting this option (on by default) lets you limit the items exported only to those items that are currently selected.