1,721,202 research outputs found
On the Modeling of Electro/Magneto-Sensitive Elastomers
No full textPh.D Thesis, University of Bologn
Modeling of a heaving buoy wave energy converter with stacked dielectric elastomer generator
No full textThis paper introduces a novel architecture of Wave Energy Converter (WEC) provided with a Dielectric Elastomer (DE) Power Take-Off (PTO) system. The device, named Poly-Buoy, includes a heaving buoy as primary interface, that captures the mechanical energy from waves, and a DE Generator (DEG), made by stacked layers of silicone elastomer, that converts mechanical energy into electricity. A mathematical model of the Poly-Buoy is proposed, which includes analytical electro-hyperlastic equations for the DEG and a linear model for wave-buoy hydrodynamics. Procedures for the design and optimization of different layouts and control strategies for the DE-PTO are introduced that specifically consider single-DEG and dual-DEG architectures. A numerical case study is also reported for specific geometrical dimensions of the buoy and specific wave climate data
Biologically Inspired Joints for Innovative Articulations Concepts
No full textFinal Report for the European Space Agency, activity AO/1-4532/03/NL/MV – ARIADNA ID: 04/640
Parallelogram-shaped dielectric elastomer generators: Analytical model and experimental validation
No full textDielectric elastomers are smart materials that can be used to conceive solid-state electromechanical transducers such as actuators, sensors, and generators. Dielectric elastomer generators, in particular, are very promising for energy harvesting applications because they potentially feature large energy densities, good conversion efficiencies, good shock and corrosion resistance, and low cost. In this article, a novel concept of parallelogram-shaped dielectric elastomer generator is presented and analyzed. Parallelogram-shaped dielectric elastomer generators are rotary variable capacitance transducers, which are made by planar dielectric elastomer membranes that are covered with compliant electrodes and clamped along their perimeter to the links of a parallelogram four-bar mechanism. First, an analytical model for the electro-hyperelastic response of the parallelogram-shaped dielectric elastomer generator is described and used to assess the maximum theoretical performances of the device. Then, an experimental case study with a parallelogram-shaped dielectric elastomer generator prototype featuring a natural rubber dielectric elastomer membrane and carbon conductive grease electrodes is presented. Simulation and experimental results demonstrate the practical feasibility of the parallelogram-shaped dielectric elastomer generator concept
Simplified model of offshore Airborne Wind Energy Converters
No full textAirborne Wind Energy Converters (AWECs) are promising devices that, thanks to tethered airborne systems, are able to harvest energy of winds blowing at an altitude which is not reachable by traditional wind turbines. This paper is meant to provide an analysis and a preliminary evaluation of an AWEC installed on a floating offshore platform. A minimum complexity dynamic model is developed including a moored heaving platform coupled with the dynamics of an AWEC in steady crosswind flight. A numerical case study is presented through the analysis of different geometrical sizes for the platform and for the airborne components. The results show that offshore AWECs are theoretically viable and they may also be more efficient than grounded devices by taking advantage of a small amount of additionally harvested power from ocean waves
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