Design of improved viscoelastic dampers exploring 3D printing technology

Vibration attenuation based on viscoelastic dampers have long been used to cope with a variety of industrial problems. Nonetheless, the quest for improving the effectiveness of those dampers is still an active research topic. Very often, technical and economical constraints involved in traditional manufacturing processes of more complex damping devices must be dealt with. The emergence and development of additive manufacturing technology have opened promising opportunities for innovative solutions. Among the existing technologies, PolyJet^TM is an additive manufacturing technique in which an object is built in successive layers by jetting drops of ultraviolet curable liquid photopolymers, thus enabling to create complex, non-homogenous parts, with high geometric accuracy and finishing quality. This paper intends to fulfil some research needs by reporting investigations conducted to assess the damping performance of a novel design of viscoelastic surface treatment, named herein “lamellar damper”, which offers the possibility of achieving vibration mitigation goals by setting the design parameters. The research work involves both numerical modelling and experimental testing. For the later, PolyJet^TM is used to manufacture prototypes of the lamellar damper. Confined to beam-like structures, the study comprises: 1) the development of low- and high-fidelity finite element models intended to predict the damping levels provided by the dampers considered, in comparison with conventional constrained layer dampers; 2) the realization of vibration tests on a beam to which 3D-printed lamellar dampers are applied, aiming at obtaining a set of frequency response functions and quantifying the associated natural frequencies and modal damping ratios. In addition, simulations are performed to assess the influence of relevant design parameters on the damping performance of lamellar dampers. The conclusions of the investigation indicate that the lamellar damper can provide improved damping performance and that PolyJet^TM can be a viable and efficient process for the manufacturing of those dampers for practical applications.