Institute of Fundamental Technological Research

A method of vibration reduction based on activation of an MRE block that couples twin cantilever beams at their free ends is investigated. Four types of magnetorheological elastomers have been manufactured, and their rheological properties in a range of magnetic field intensities are established. Free vibrations of several double-beam structures with controllable damping members made of these MREs are investigated, and a method of semiactive control of such structures is proposed. The effects of compression of the elastomers and alignment of the magnets used to activate them are reported. The mathematical modeling of the system is verified experimentally.

Polyamide 11/multi-walled carbon nanotubes nanocomposite fibers with weight fraction 2, 4, and 6 wt.% and diameter 80 μm were prepared with a twin screw mini-extruder. The morphology and degree of dispersion of the multi-walled carbon nanotubes in the fibers was investigated by using scanning and transmission electron microscopy. In turn, the molecular structure was indicated by using wide-angle x-ray scattering and correlated with thermal analysis. It was found that carbon nanotubes lead to the formation of α phase in the fibers and they show medial level of alignment within the length of the fiber. Mechanical analysis of the fibers shows that apart from the crystallinity content, the tensile strength is strongly dependent on the macroscopic defects of the surface of the fibers. Nanocomposite fibers based on polyamide 11 with carbon nanotubes can be used as a precursor for non-woven or woven fabrics manufacturing process.

aerospace, electron microscopy, nanomaterials, thermal analysis, x-ray