Optimizing strain energy extraction from multi-beam piezoelectric devices for heavy haul freight cars

Abstract

Heavy haul trains used to transport commodities are generally very long and operated by a single individual. Owing to high noise levels from the rolling stock displacement, the driver cannot notice failures in the compartments. It is practically impossible to visually inspect the wagons located far from the locomotive. Sensors that can measure in-train forces may improve the train's operation, indicating potential failures and preventing accidents and derailments. However, the freight cars employed in most of the railroads are not equipped with electric power sources, making inspections unlikely. Therefore, an energy harvesting system must be developed for the sensors to avoid the need for periodic battery charging or replacement. As a high level of kinetic energy is present in the rolling stock, a vibration energy harvester (VEH) system is an acceptable alternative. Among VEH devices, multi-beam piezoelectric materials used in planar zigzag (PZ) or orthogonal spiral outer fixed (OSo) configurations can be effective alternatives. These can be powered by low-frequency strains readily available in the freight cars. This study investigates the optimum geometries of PZ and OSo aiming to increase the generated power and minimize the structure mass with a focus on their application to ore wagons. Among the optimum solutions, the OSo geometry generates the maximum power, up to 20.93 mW, which is sufficient to feed some critical devices. Conversely, the PZ configurations present the highest energy density, up to 16.595 mW/kg(m s −2) 2 , which allows for a more suitable solution to be combined in serial and/or parallel pack configurations.

Design of an Aftermarket Hybridization Kit: Reducing Costs and Emissions Considering a Local Driving Cycle

“…The convergence is defined by the stagnation of the evolution process, which is characterized by the repetition of the Pareto frontier [33,59,65] for over 20 generations of 80 new simulated solutions (crossover and mutation). Figure 7 shows the optimization flowchart according to the applied method.…”

Benefits and Limitations of using Several Piezoelectric Cantilever Elements for Harvesting Vibration Energy in Moving Freight Cars

“…One significant area of concern pertains to freight cars, where incidents of wagon derailment are still reported [2]. It is surmised that such derailments could potentially be mitigated through vigilant monitoring of causative factors, including damaged rails, wheel or axle failure, and non-uniform braking [3]. Hence, deploying robust monitoring systems is imperative, not only for detecting these failures but also for timely communication of these incidences, thereby averting derailments or other train faults.…”

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Powering the WSN Node for Monitoring Rail Car Parameters, Using a Piezoelectric Energy Harvester

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