An experimental study on shift in natural frequency of sandwich beam with elastomeric core embedded with SMA wires

In this paper an experimental study of dynamic behavior of sandwich beam with elastomeric core embedded with shape memory alloy (SMA) wires is done. The three pre-strained Ni 50%, Ti 50% wires with 10 mm offset from neutral axis are used. The wires are embedded along the length of rectangular beam and elastomeric core is sandwiched between two copper plates. The beam is tested for free-free boundary condition and average 48% shift in natural frequency is observed when the stiffness of beam is changed by heating the wire by 4.5 amp electric current. The effect of actuation current on damping factor and time required to regain its original frequency, after making current zero, is estimated and presented.