From attached shape memory alloy wires to integrated active elements, a small step? Impact of local effects on direct integration in fiber reinforced plastics

Abstract

In this publication, major challenges occurring during integration of active elements made from shape memory alloys in fiber reinforced plastics are discussed. Tightly focused experimental tests with a properly chosen setup enable spatially resolved stress and temperature measurement, revealing important material characteristics which have to be considered for the design of integrated active elements. The detwinning process of the martensite during elongation of the shape memory alloy elements shows a nucleation, leading to critical inhomogeneous strain distribution. By investigating the strain rate-dependent behavior the nucleation mechanism is revealed. The measured local strain and actuation behavior of the active elements and its influence on the performance of hybrid structures is discussed. Also a clamped heating process is investigated to show how stress redistribution affects the processing of hybrid structures during a hot curing process.