Fabrication technique of SMA/CFRP smart composites

In recent years, pre-strained TiNi shape memory alloys (SMA) have been used for fabricating smart structure with carbon fibers reinforced plastics (CFRP). However, since the curing temperature of CFRP is higher than the reverse transformation temperatures of TiNi SMA, special fixture jigs have to be used for keeping the pre-strain during fabrication, which restricted its practical application. We have developed a new method to control the transformation temperatures of SMA by proper thermo-mechanical treatments and composition adjustment, which is suitable to fabricate SMA/CFRP smart composite with a curing temperature of 130C. Furthermore, we tried to develop a new fabrication technique which is also suitable to fabricate SMA/CFRP smart composite with a curing temperature of 180C. It was found that by using cold drawn ultra-thin TiNi wires, TiNi/CFRP composites with a curing temperature of 180C could be fabricated without special fixture jigs. The damage suppression effect by embedded ultra-thin wires in the smart composite was confirmed.