In the program parts Natural Vibrations, Forced Vibrations, and Equivalent Loads of the RF-DYNAM Pro add-on module, a linear calculation is performed. Nonlinearities, such as failure under tension or nonlinear material properties, are ignored. For example, cables or tension members are replaced by the Truss member type. This results from the calculation methods: Both the natural vibration analysis and the response spectrum analysis are purely linear methods.
The "Nonlinear Time History Analysis" program part provides a nonlinear time history analysis of time diagrams (any excitation of the structure) and accelerograms (excitation of supports) using an implicit and explicit analysis. In this case, many nonlinearities that can be defined in RFEM 5 or RSTAB 8 are taken into account.