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Deflection and stress calculated from an experimentally validated, high-fidelity finite element model (FEM) of a photovoltaic module experiencing mechanical load was compared to results from a simplified FEM treating the module laminate as a homogenized composite using a rule of mixtures approach, and further compared to analytical calculations treating the module as a Kirchoff-Love flat plate. The goal of this study was to determine the error incurred by analyzing module mechanics with varying levels of simplification, since resolving the aspect ratios of a module is computationally expensive. Homogenized FEMs were found to underpredict peak deflection under a 1.0 kPa load by between 13 and 19% for lower and upper bound application of the rule of mixtures. However, module shape was captured, implying that a useful replication of a resolved model could be achieved with a reduced, calibrated material stiffness. Homogenized stress results captured glass layer tensile stress components to within 46 to 52% at a sample location of interest, though agreement was poor through the remainder of the laminate due to the lack of material resolution. For plate theory, deflection was overpredicted by 45 to 67% for upper and lower bound homogenizations, and frame-adjacent module shapes were not adequately replicated. Stress results mirrored FEM trends but magnitudes were not well correlated to resolved model values. These results support the use of homogenized laminate models for module shape derivation, though resolved models remain necessary for stress analyses. The accuracy of plate theory was found to be inadequate for most applications. [ABSTRACT FROM AUTHOR]

The influence of carbon nanotube dispersion techniques (surfactant-assisted dispersion, ultrasonication and magnetic stirring) and surface functionalization of carbon nanotubes on mechanical properties of nanocomposites fabricated via powder metallurgy techniques is characterized. Functionalized multiwalled carbon nanotubes dispersed using a combination of techniques results in Al/functionalized multiwalled carbon nanotube composites with excellent microstructure and enhanced mechanical properties. Nonfunctionalized carbon nanotubes dispersed using zwitterionic surfactants show good dispersion patterns on Al powder surfaces and results in composites with good strength and relative densities are also obtained. Carbon nanotubes dispersed solely via shear mixing techniques resulted in highly embrittled composites with poor microstructure. Also discussed in this study is the usefulness of scanning electron microscopy in conjunction with image analysis techniques in characterizing porosity in Al/carbon nanotube composites. [ABSTRACT FROM AUTHOR]

Analogous to mechanical systems, modeling the electromagnetic (EM) performance of large and complex metamaterial structures requires the use of effective-medium/constitutive properties. Constitutive properties are critical for efficiently bridging the gap between subwavelength geometry and performance at the mesoscale. In this article, the temperature-dependent effective medium properties for a metamaterial electric-inductive-capacitive (ELC) resonator are described analytically. ELC structures are commonly used in metamaterial designs to provide a tailored electric response to EM waves. An equivalent circuit model, coupled with analytic expressions for the capacitances, inductance, and resistance of the ELC resonator, is utilized to describe how thermally induced mechanical strain and changes in material properties manifest as temperature-dependent permittivity and permeability curves for the metamaterial. The resulting analytic expressions account for the effects of spatial dispersion and losses. This article also details how the process may be expanded to similarly describe the temperature-dependent constitutive properties of metamaterial magnetic resonators. [ABSTRACT FROM PUBLISHER]