Browsing by Subject "Adaptivity"

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    Adaptive thermally tunable radiative cooling with angle insensitivity using phase-change-material-based metasurface
    (Institute of Physics Publishing Ltd., 2023-11-17) Boşdurmaz, Ekin Bircan; Ghobadi, Amir; Özbay, Ekmel
    Radiative cooling is the passive cooling of a material with the help of a specific spectral response to emit thermal energy into space through atmospheric transparency windows. However, most of the proposed designs have no dynamically tunable emission response. In this paper, we present a feasible inverse pyramid structure made of a phase change material (PCM) on top of a metallic mirror to realize an adaptive radiative cooler with almost angle-independent emission response. The design uses the thermally controlled PCM called Samarium nickelate (SmNiO3) to actively tune the spectral response of the design, which, in turn, allows the design to radiatively cool itself. The emission response of the design is compatible with atmospheric transmissive windows. As the design heated up to higher temperatures, the peak of the emission spectrum red-shifts and moves toward the atmospheric transparency window.
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    Smart composites with tunable stress–strain curves
    (Springer, 2020) Özcan, Mert; Çakmakçı, Melih; Temizer, İlker
    Smart composites with tunable stress–strain curves are explored in a numerical setting. The macroscopic response of the composite is endowed with tunable characteristics through microscopic constituents which respond to external stimuli by varying their elastic response in a continuous and controllable manner. This dynamic constitutive behavior enables the composite to display characteristics that cannot be attained by any combination of traditional materials. Microscopic adaptation is driven through a repetitive controller which naturally suits the class of applications sought for such composites where loading is cyclic. Performance demonstrations are presented for the overall numerical framework over complex paths in macroscopic stress–strain space. Finally, representative two- and three-dimensional tunable microstructures are addressed by integrating the control approach within a computational environment that is based on the finite element method, thereby demonstrating the viability of designing and analyzing smart composites for realistic applications.