Evaluation of segmented active constrained layer damping treatments that include bonding layer strain energy

The primary objective of this study is to develop a more accurate research and design tool than those in the currently available literature for active constrained layer damping treatments applied in bending. A five layer beam finite element model is presented that includes bonding layer strain energy and extends current finite element models for Euler-Bernoulli beams with segmented active constrained layer damping treatments. Active constrained layer damping utilizes modem piezoelectric materials as the constraining layer for these types, of damping treatments. Preliminary studies have confirmed that strains in the bonding layers can have a significant effect on damping ratios at the fundamental modal frequency, especially when relatively thin compliant piezo materials are used for constraining layers. Previous researchers that have developed three layer finite element models assumed perfect no-slip adhesion between adjacent surfaces of the beam, viscoelastic layer, and constraining layer. In certain instances this can contribute to reduced accuracy when predicting damping. The effectiveness of the finite element model is validated experimentally for both active and passive constraining layers. The damping is represented using anelastic displacement fields (ADF) to model the frequency dependent stiffness and damping properties in viscoelastic materials as developed by Lesieutre and Bianchini(26).