Formation Behavior of Shape Recovery Force in Tini Fiber Reinforced Smart Composite

Abstract

The shape recovery force is generated by joule heating it to the shape-memory alloy (SMA) wire which pre-strain of several % of the burial in the resin matrix, and the development of smart composite materials which achieve intellectual effects of the spread obstruction of the crack and the self-restoration, etc. is advanced. Authors try to measure the displacement of the composite material when Joule heating it, and to evaluate the shape recovery force from the amount of shrinkage, and have obtained quantitative information on the relations etc. between the structure of the composite material and the heating condition, etc. [1,2]. However, because many of calories generated from SMA by Joule heating are spent on the heating of the matrix, the reverse-transformation temperature arrival time of SMA is delayed under the low temperature environment. Therefore, because the thermal expansion of the matrix is superior, evaluating the formation behavior of the shape recovery force from the displacement measurement of the composite material becomes difficult. Then, it was tried to evaluate the behavior of the shape recovery force in the smart composite material which reversely transformed SMA by Joule heating in this research by measuring the change in the electrical resistance which related closely to phase transformation of SMA in a wide-ranging operation environment.