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Tobushi H.,Aichi Institute of Technology | Hayashi S.,SMP Technologies Inc. | Pieczyska E.,Polish Academy of Sciences | Date K.,Ochiai Nexus Co. | Nishimura Y.,Aichi Institute of Technology
Materials Science Forum | Year: 2011

The SMC belt composed of two kinds of SMAs and SMP was fabricated and the three-way movement and recovery force in bending were investigated. The results obtained can be summarized as follows. (1) The three-way bending movement was achived during heating and cooling based on the characteristics of the SMA tapes and the SMP sheet. (2) The recovery force increased during heating and decreased during cooling. The recovery force was evaluated by the proposed simple model. © (2011) Trans Tech Publications, Switzerland. Source


Kuriyagawa M.,Kanazawa University | Kawamura T.,Kanazawa University | Hayashi S.,SMP Technologies Inc. | Nitta K.-H.,Kanazawa University
Journal of Materials Science | Year: 2011

The mechanical yielding behavior of the shape memory polyurethane (SMP) and its composite samples were investigated to verify the effect of addition of hindered phenol. The composite samples were prepared using SMP as matrix and hindered phenol (AO-80) as filler, and then tensile tests were carried out at a range of temperatures and with different fixed crosshead speeds. According to the tensile data at 25 °C, the yield stress was increased by adding AO-80. In terms of the Eyring theory, the activation volume of deformation units decreased with increase of the amount of AO-80 added. This is because the packing of the hard segments is enhanced by addition of AO-80. Consequently, it was suggested that the yield process is caused by the rotation of hard segment domains within the deformed plastic domains composed of glassy soft segments. © Springer Science+Business Media, LLC 2010. Source


Tobushi H.,Aichi Institute of Technology | Hayashi S.,SMP Technologies Inc. | Sugimoto Y.,Aichi Institute of Technology | Date K.,Aichi Institute of Technology
Materials Science Forum | Year: 2010

The shape memory composite (SMC) with shape memory alloy (SMA) and shape memory polymer (SMP) was fabricated, and the 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 and superelasticity were heat-treated to memorize the round shape, respectively. The shape-memorized round SMA tapes were sandwiched between the SMP sheets, and the SMC belt was fabricated. (2) The two-way bending deformation with an angle of 56 degrees is observed during heating and cooling. (3) If the SMC belt is heated and cooled by keeping the form, recovery force increases during heating and decreases during cooling. © (2010) Trans Tech Publications. Source


Kuriyagawa M.,Kanazawa University | Kawamura T.,Kanazawa University | Hayashi S.,SMP Technologies Inc. | Nitta K.-H.,Kanazawa University
Journal of Applied Polymer Science | Year: 2010

Reinforcement of polyurethane-based shape memory polymer materials was investigated by adding hindered phenol compounds and silica particles. According to dynamic mechanical analysis, these fillers had no effect on the glass transition temperature and the activation energy of soft segments, indicating that the fillers have no ability to influence the molecular mobility of soft segments. It was found from the tensile tests that the yield stress was increased primarily by addition of the hindered phenols rather than the silica particles, whereas Young's modulus was enhanced by the silica particles rather than the hindered phenols. VC 2010 Wile y Periodicals, Inc. Source


Pieczyska E.A.,Polish Institute of Fundamental Technological Research | Maj M.,Polish Institute of Fundamental Technological Research | Kowalczyk-Gajewska K.,Polish Institute of Fundamental Technological Research | Staszczak M.,Polish Institute of Fundamental Technological Research | And 5 more authors.
Smart Materials and Structures | Year: 2015

In this paper extensive research on the polyurethane shape memory polymer (PU-SMP) is reported, including its structure analysis, our experimental investigation of its thermomechanical properties and its modelling. The influence of the effects of thermomechanical couplings on the SMP behaviour during tension at room temperature is studied using a fast and sensitive infrared camera. It is shown that the thermomechanical behaviour of the SMP significantly depends on the strain rate: at a higher strain rate higher stress and temperature values are obtained. This indicates that an increase of the strain rate leads to activation of different deformation mechanisms at the micro-scale, along with reorientation and alignment of the molecular chains. Furthermore, influence of temperature on the SMP's mechanical behaviour is studied. It is observed during the loading in a thermal chamber that at the temperature 20 °C below the glass transition temperature (Tg) the PU-SMP strengthens about six times compared to the material above Tg but does not exhibit the shape recovery. A finite-strain constitutive model is formulated, where the SMP is described as a two-phase material composed of a hyperelastic rubbery phase and elastic-viscoplastic glassy phase. The volume content of phases is governed by the current temperature. Finally, model predictions are compared with the experimental results. © 2015 IOP Publishing Ltd. Source

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