Damping effects are of great interest for structural analysis and evaluations. Structuralmodal damping characteristics can be obtained from experiments. This paper introducesnew possibilities for the modelling of the damping of a dynamic system with classical normalmodes and provides an overview of the known methods for formulating a damping matrixbase with experimental modal damping values. The proposed method offers an opportunityto extrapolate modal damping values for unmeasured modes by a regression method basedon the measured modal properties. The points of view on the choice of an analytical formfor damping regression functions are examined. An analytical form of regression functionscan be chosen as the modal decay rate versus the square of the frequency or the modaldamping ratio versus the frequency. Damping regressions can be performed based ona group of typical vibration modes, such as bending, torsion and lateral, symmetrical oranti-symmetrical modes. The regression data obtained for the damping constants can thenbe applied in a finite element model for further structural analysis.
