Modal Damping Predictions Using Substructure Testing

A method is presented for predicting the modal damping of structures using a combination of analysis and tests of substructures. Damping characteristics of simple substructures and joints are determined by the test program, and analysis is used to predict the modal damping coefficients as a function of the peak kinetic energy of vibration in the mode. Both the magnitude and the form of the damping can be predicted before full-scale test hardware becomes available.