Investigation on forced vibration response of micro rubber/nano silica added carbon composite beams for structural applications

摘要

Suppression of vibration is one of the functional requirement in structures subjected to dynamic conditions like machine tools, automobile parts etc. To impart increased dynamic stiffness and strength to woven fabric carbon epoxy composite structures, micro rubber particles of average size 5μm and 20nm nano silica particles were added and its dynamic response was evaluated by experimental forced vibration study. The carbon epoxy composite beams were compared with carbon composite containing 9 wt. % of micro rubber particles and 11wt. % of nano silica particles. Carbon epoxy beams were fabricated by hand layup method by considering Box and Channel cross sectional shape. A fiber volume fraction of 40% and a matrix volume fraction of 60% were preferred as a composition for all considered beams. Six-layered carbon/epoxy beam with uniform cross-sectional area, height to width ratio, and moment of inertia were considered. Forcing sine wave motion was given to the composite beams through higher order stinger which is connecting between free end of the beam and electrodynamic shaker. The forced vibration test was conducted for the frequency range from 50 to 80 Hz with two different forcing amplitudes of 0.05 mm and 0.1mm. The responses show the variation in dynamic performance of carbon when compared with dedicated carbon beam. Closed cross sectional box shape shows improved performance than open channel shaped beam under forced vibration condition.