Two-Way Bending Properties of Shape Memory Composite with SMA and SMP

Abstract

A shape memory composite (SMC) was fabricated with a shape memory alloy (SMA) and a shape memory polymer (SMP), and its two-way bending deformation and recovery force were investigated. The results obtained can be summarized as follows: (1) two kinds of SMA tapes which show the shape memory effect (SME) and superelasticity (SE) were heat-treated to memorize the round shape. The shape-memorized round SMA tapes were arranged facing in the opposite directions and were sandwiched between the SMP sheets. The SMC belt can be fabricated by using the appropriate factors: the number of SMP sheets, the pressing force, the heating temperature and the hold time. (2) The two-way bending deformation with an angle of 56 degrees in the fabricated SMC belt is observed based on the SME and SE of the SMA tapes during heating and cooling. (3) If the SMC belt is heated and cooled by keeping the bent form, the recovery force increases during heating and degreases during cooling based on the two-way properties of the SMC. (4) The development and application of high-functional SMCs are expected by the combination of the SMA and the SMP with various kinds of phase transformation temperatures, volume fractions, configurations and heating-cooling rates.

The Effect of POSS Type on the Shape Memory Properties of Epoxy-Based Nanocomposites

“…Hard segments are the net points that determine the SMP’s permanent shape, while soft segments are able to reduce stiffness upon a particular stimulus, allowing the polymer to be programmed into its temporary shape [ 8 ]. Upon exposure to specific stimulus, the molecular switches are triggered, and strain energy that was stored in the temporary shape is released, which consequently leads to shape recovery to the original permanent shape [ 5 ]. Since most polymers possess either glass transition or melting temperatures, a typical external stimulus is the temperature [ 9 ].…”

Functionally-graded shape memory polymer board

“…The dependence of mechanical properties on temperature is therefore quite opposite between the SMA and the SMP. If the shape memory composites by combing the SMA and the SMP are developed, the new and higher functions can be used (Sterzl et al, 2003;Kawai, 2006;Manzo and Garcia, 2007;Browne et al, 2009;Tobushi et al, 2006;Tobushi et al, 2009). On the other hand, if the new SMAs or SMPs are fabricated by combing the materials with various phase transformation temperatures, the functionally-graded shape memory materials can be developed.…”

Investigation on the Cyclic Response of Superelastic Shape Memory Alloy (SMA) Slit Damper Devices Simulated by Quasi-Static Finite Element (FE) Analyses

“…As shown in the figure, superelastic Nitinol SMAs that typically occur at a temperature limit above the austenite phase transformation (A f ) do not exhibit any residual deformation without additional heating, even after applying substantial strain, ranging from 6% to 8%. This material behavior makes a significant contribution toward providing an excellent recentering capability, as well as supplemental energy dissipation for the entire frame structure, when such superelastic SMA materials are used in the damper device [ 11 , 12 ]. In this study, slit damper devices fabricated with superelastic SMA materials are consequently introduced to attain both the establishment of additional damping and the mitigation of residual inter-story drifts.…”