User Programmable Feature Programming in ANSYS
Implementation of New Elements in ANSYS
Sometimes engineers need to have their own element within the ANSYS Mechanical environment. Examples can be found in the bearing industry where long term experience is available in the stiffness description of roller bearings. Sometimes this information is available based on empirical formulas, sometimes the information about the nonlinear stiffness is available just in simple tables. The question is now how to implement this information in ANSYS using the stiffness behavior as an element.
The User-Programmable-Feature-Interface (UPF) allows us to implement own commands, own material laws and also complete new elements. Within the users element description it is possible to define an individual stiffness, mass and damping matrix that can be also depending on the underlying deformation of the structure. Since this element is fully integrated in the Newton-Raphson scheme for the solution of nonlinear problems it is also possible to implement nonlinear elements in this way.
The code itself has to be provided in the Fortran77 format. The integration of this code is done by compilation of the code fragments and linking it to the remaining ANSYS libraries. The element can also be used within the ANSYS Workbench environment by means of command snippets.