Damping characteristics of machine structures assembled by bonding: a beam in which two steel strips are partially joined by an adhesive

Machine structures assembled by adhesive bonding are expected to possess a high damping capacity because of the high damping capacity of the adhesive. In this study, the damping characteristics of a beam in which two steel strips were partially joined by an adhesive have been investigated. The primary aim of this study was to clarify the damping characteristics of adhesively bonded structures and to establish an estimation method for the damping capacity. In the analysis, strain energy distributions in the adhesively bonded beam in motion are analyzed by the finite element method. Then the damping capacity of the beam is derived using the strain energies and damping ratios of the two materials, i.e. the steel strips and the adhesive, which were obtained beforehand in independent experiments. The validity of the proposed estimation method for the damping capacity and the effects of the thickness of the adhesive and vibration modes on the damping capacity were confirmed by experiments. Satisfactory agreement was shown by comparing the estimated values of the damping capacity of the beam with the experimental results. Furthermore, the temperature dependence of the damping capacity was examined.