Vibrational characterization of in-situ stair performance using energy-harvester data

Vibration performance and energy harvesting potential of two in-situ stairs is evaluated using voltage output of an electromagnetic induction harvester prototype. First, the validation and benchmarking procedure is provided for a prototype electromagnetic induction harvester to assess 1) performance as a quantitative sensor for vibrations and 2) feasibility as a low-demand energy harvester. Secondly, the dynamic characteristics of two in-situ stairs are evaluated and compared to FEA and simplified analytical single-degree of freedom (SDOF) models. Lastly, the experimental dynamic response of the stairs is presented by using a single parameter: peak voltage response with the two-fold purpose of describing the performance and assessing the feasibility for energy harvesting. Using optimal mass and stiffness properties from previous research, the maximum voltage output under two time-history load cases reached 110mV per coil and was correlated to equivalent sinusoidal peak acceleration (ESPA) of 0.2% g for comparison to vibration criteria showing that both stairs are acceptable (< 1–2% g). Based on results, an improved harvester is being optimized for total power output, instead of only voltage.