Modeling of frequeney-dependent viscoelastic materials for active-passive vibration damping

This work intends to compare two viscoelastic models, namely ADF and GHM, w hich account for frequency dependence and allow frequency and time-domain a nalysis of hybrid active-passive damping treatments, made of viscoelastic l ayers constrained with piezoelectric actuators. A modal strain energy (MSE) based iterative model is also considered for comparison. As both ADF and G HM models increase the size of the system, through additional dissipative c oordinates, and to enhance the control feasibility, a modal reduction techn ique is presented for the first time for the ADF model and then applied to GHM and MSE ones for comparison. The resulting reduced systems are then use d to analyze the performance of a segmented hybrid damped cantilever beam u nder parameters variations, using a constrained input optimal control algor ithm. The open loop modal damping factors for all models match well. Howeve r due to differences between the modal basis used for each model the closed loop ones were found to be different.