Design of multi-state and smart-bias components using Shape Memory Alloy and Shape Memory Polymer composites

摘要

A Multifunctional Smart Material System (MSMS) consists of two or more different smart material phases in the form of a hybrid system, in which every phase performs a different but necessary function. In this work, thermally responsive Shape Memory Alloys (SMAs) and Shape Memory Polymers (SMPs) are combined to form a MSMS. The transformation temperatures martensitic start (M_s), martensitic finish (M_f), austenitic start (A_s) and austenitic finish (A_f) of SMA and the glass transition (T_g) for the SMP play a critical role in designing such a MSMS. Multi-state smart bias systems with varying stiffnesses can be obtained by varying the T_g of SMP between the transformation temperatures M_f and A_f of SMA. Guidelines to form such MSMS have been established by estimating the volume fractions of the individual constituents. Various ideas for "smart-bias" tools/devices have been proposed, such that they can operate under three different temperature regimes, with one material constituent being passive and the other active at a given temperature.