A gift from Professor Felippa to the OpenSees endeavor.
The template plane stress triangle with drilling DOFs.

To find out more about this element, go to 
Professor Felippa's publications web page at:

http://caswww.colorado.edu/Felippa.d/FelippaHome.d/Felippa.Publications.html

All other questions should be directed to jeremic @ ucdavis.edu.
