There are cases when you need to use elements with elliptical forms. In order to create a plate that has an elliptical outline or a curved beam that follows an elliptical path you must create an elliptical polyline.
AutoCAD usually draws ellipses that are not made of polylines and cannot be used as the basis of a plate or beam. Therefore you must tell AutoCAD to draw ellipses as polylines.
To create ellipses as polylines enter the command PELLIPSE on the AutoCAD command line. The program will ask you to enter a value and this must be 1.
Once the value is set, you can make ellipses and edit them to create the form that you need.
After the editing is finished, the new forms can be converted into plates or beams using the command for each type of element.