Experimental modal analysis performed by high-speed digital image correlation system

• Authors used digital image correlation system for experimental modal analysis (EMA).
• For the modal parameters estimation an original program called Modan 3D was created.
• Modan 3D directly allows visualization of particular modes and damping ratios.
• Its function was verified on two specimens by conventional experimental technique.
• The proposed methodology markedly reduces time for EMA performing.

In this paper a modification of a high-speed correlation system for the purposes of mechanical structures modal parameters estimation is described. Together with hardware modification an original version of a program Modan 3D was created, which is a complex tool for execution of an experimental and operational modal analysis. In the contribution the authors present just some information about a part of the program used for the experimental modal analysis. They describe algorithm required for a calculation of a normal mode indicator function (NMIF), a complex mode indicator function (CMIF), damping ratios as well and visualization of the mode shapes. A functionality of the program was tested during the analysis of two thin steel samples. A reliability of the reached results was verified by means of a system specialized for vibration analysis.