A magnetostrictive system in bridges converts structural vibrations into electrical energy using the principle of magnetostriction. Magnetostriction is a phenomenon in certain materials where their shape changes in response to an applied magnetic field. When these materials are subjected to mechanical stress or vibrations, they experience changes in their magnetic properties, which, in turn, induce electrical voltage in nearby coils.
Here's a basic explanation of how a magnetostrictive energy harvesting system works in bridges:
Magnetostrictive Material: The system uses a magnetostrictive material, such as Terfenol-D or other suitable alloys, as the core component. This material is chosen for its ability to undergo magnetostriction efficiently.
Sensing Mechanism: The magnetostrictive material is integrated into the bridge structure, often in the form of rods or strips. As the bridge experiences structural vibrations due to traffic loads, wind, or other external forces, these vibrations cause mechanical stress in the magnetostrictive material.
Magnetic Field: Surrounding the magnetostrictive material are one or more coils of wire. These coils serve as the primary component of the electrical generator. When a current passes through these coils, they generate a magnetic field.
Induction: The mechanical stress induced in the magnetostrictive material by the vibrations causes changes in its magnetic properties, altering its magnetic field.
Electrical Output: The changing magnetic field in the magnetostrictive material interacts with the coils, inducing an electrical voltage across them through electromagnetic induction. This induced voltage results from the dynamic fluctuations of the magnetic field as the magnetostrictive material undergoes stress and relaxation during vibrations.
Harvesting Electrical Energy: The induced voltage across the coils can be collected and harnessed as electrical energy. This energy can then be used to power various devices or stored in batteries for future use.
The magnetostrictive energy harvesting system provides a way to convert the ambient mechanical vibrations in a bridge structure into useful electrical energy, making it a potential solution for sustainable power generation in areas with high traffic or frequent structural vibrations. By converting wasted energy from vibrations into electricity, this technology can contribute to reducing the environmental impact of infrastructure and improve the overall efficiency of energy usage.