Enhancement of damping characteristics of polymer cantilever with mr fluid and piezoelectric mfc

Abstract

The vibration damping and natural frequencies of cantilever newlinebeams composed of surface layers such as Polylactic Acid (PLA) and newlinePolyvinyl Chloride (PVC) are experimentally studied with newlineMagnetorheological (MR) fluid core. Polylactic acid (PLA) is an newlineenvironmentally friendly, biodegradable, and low-cost thermoplastic material newlinesuitable for 3D printing. Complex shapes can be easily produced and hence newlinePLA has been used for many applications. This study aims to improve newlinedamping using MR Fluid for PLA and PVC beams. The magnetic field is newlineapplied by using permanent magnets while the magnetic field strength is newlinevaried by changing the distance between the permanent magnets. The newlinedamping ratio for PLA and PVC cantilever structures with MR Fluid newlineincreased by 122.22 percent and 94.87 percent, as the magnetic field intensity newlinevaried from 0Gauss(G) to 600Gauss(G). Based on the experimental damping newlineratio, the theoretical amplitude at the resonance condition is analyzed. The newlinevibration amplitude is lowered for PLA and PVC cantilevers by 63.44 newlinepercent and 66.62 percent over the same variation in magnetic field strength. newlineThe natural frequencies obtained experimentally (0G) are validated with newlinenumerical modal analysis. This study also presents the damping newlinecharacteristics of two robotic gripper fingers. The first gripper is composed of newlinea PLA surface layer and a magnetorheological (MR) fluid core and the newlinesecond gripper is composed of a PLA surface layer bonded to a surface of newlineunimorph piezoelectric Macro Fibre Composite (MFC). The electric field is newlineapplied by using a micro-amplifier and regulated using data acquisition newlinesystems. The damping ratio and vibration amplitude suppression for the PLA newlinegrippers was increased as the magnetic field strength changed from 0G to newline600G (MR) and as the electric field changed from 0V to 360V (MFC). newline newline