Design of smart sandwich structures enhanced by multi-functional shear thickening fluids (M-STFs): Anti-vibration and electrical conductivity

This study investigates a novel concept of integrating multi-functional shear thickening fluids (M-STFs) into the core layer of a sandwich composite consisting of polyvinyl chloride (PVC) foam and aluminum face sheets to enhance the vibration damping of the structure. First, high-performance STF (60 wt% SiO2) was produced and M-STFs were created by gradually adding multi-walled carbon nanotubes (MWCNTs) up to 1.5 wt%. The percolation threshold range was obtained and the effects of increasing MWCNTs up to 1.5 wt% to STF on reducing electrical resistance and improving rheological properties were investigated. Secondly, sandwich structures consisting of aluminum face sheets and PVC foam core layers were made. The smart nanofluids STF and M-STFs were added to sandwich structures through the grooves created in the PVC foam core. Six different configurations were designed to investigate the effects of adding STF and M-STFs on the vibration damping performance of the sandwich structures. The model analysis results showed that the M-STFs integration into the core layer of designed sandwich structures significantly enhances the damping ratio of the structures as well as provides a higher stiffness coefficient. It was observed that the sandwich structure filled with 1.0 wt% MWCNT exhibits the highest damping ratio and stiffness.