<p>Fluidic isolators are viscous devices that attenuate vibrations by dissipating energy through fluid flow by elastic deformation of the device to generate pressure gradients that result in energy dissipation. Although this class of isolators could offer improved performance capabilities, traditional manufacturing processes cannot often produce such complex geometries due to design complexities of ideally desired internal geometries. These devices are often made of several subcomponents, thus, they suffer from a limited, and part-dependent lifetime, as well as complex maintenance processes. This original research presents a novel monolithic fluid-based vibration isolator that is designed for metal additive manufacturing processes. Laser powder bed fusion is utilized to build a compliant device geometry that can offer broadband isolation capabilities. The device has a relatively simple construction with two chambers connected with conformal channels. The chambers are filled with a viscous Newtonian fluid and are connected by a long thin channel that coils around their periphery. The part was designed to print without the need for any internal supports and ease of trapped powder removal. The PROX DMP 320 Direct metal printing 3D printer was used to manufacture the isolator using Ti64Al4V alloy. This device can be tuned to specific excitation frequencies by changing design parameters such as chamber dimension, chamber material, fluid viscosity, and channel geometry. Axial elastic deformation of the device leads to a strain gradient between the upper and the lower chamber via a bulging bridge mechanism, thus causing a volumetric change that will drive the fluid to flow. The inertial movement of the fluid is tuned to provide isolation at a specific target frequency, as well as a damped response over a specific frequency range and experiments&nbsp;are conducted to evaluate the vibration response of the device. Two specimens are used, one without fluid and the other filled with fluid. A vibration shaker stinger is mounted on one side of the isolator, while the other side is mounted on a fixed support. The isolator is excited via a point load harmonic input while the input and reaction forces are recorded, as well as the acceleration on the input side. The frequency response of the filled fluid shows improved performance over the unfilled isolator whereby there is a clear force isolation frequency and significant damping over axial vibration modes. The utility of this isolator is discussed in fixed-wing and rotary wing applications in which reduced vibration responses via low maintenance and high lifetime isolators are often preferred.</p>

Strain-Coupled Fluidlastic Circuits Inside Metal Additive Manufactured Structures

Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2021/volume/85543

ASME 2021 International Mechanical Engineering Congress and Exposition (IMECE2021)

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