Optimal design of high damping coated mechanical components

In this work a numerical procedure for the design of highly damped multi-layer coating architectures, to be applied in thin-walled mechanic components, is proposed. Optimization restraints with respect to vibration and acoustic emission reduction in operating conditions are considered. The procedure makes use of a multi-layer beam model that takes into account of dissipative actions at the interface between different layers. Dynamic mechanical measurement tests on uncoated and coated symmetric beams are used to identify the unknown material stiffness and interface parameters needed as input by the multi-layer beam model. A virtual prototyping procedure for the simulation of the dissipative effect of different multi-layer coating architectures is proposed and experimentally validated. The damping behaviour of coated slender beam specimens is tested by means of experimental measurements. Coating solutions, based on epoxy organic polymeric materials, and some architectures employing them are presented in this work. Real application examples, concerning the acoustic emission of mechanical gear pumps adopting uncoated and coated casings are presented, by means of the comparison of sound pressure measurements, related to these different configurations, in operating conditions.