Numerical modeling of steel-framed floors for energy harvesting applications

Pedestrian movement on lightweight steel-framed floor systems can excite several vibration modes in the frequency range from 0 to 30 Hz. Although structural engineers are able to design floor systems that minimize annoying vibrations due to human activities, the frequency modes may be targeted for secondary applications such as low-demand energy harvesting. The techniques of modal analysis are useful in determining the parameters of these floor systems, with the goal of targeting resonant frequency modes for energy harvesting. Advances in vibration analysis and energy harvesting technology combined with an increasing need for sustainable energy generation have inspired recent development of intermediate scale harvesters for floor vibration. These devices necessitate accurate numerical modeling strategies for coupled steel-framed floor and harvester device systems. An accurate numerical model of a coupled floor-harvester system can provide analysis resulting in optimized and efficient designs for harvesting ambient floor vibrations suitable for energizing low demand applications. Numerical analysis of an existing experimental floor system is presented. The existing floor system was selected for analysis because its frequencies, damping ratios and mode shapes were previously obtained, allowing for focus on the numerical model. Optimization, limitations and extensions of the numerical model and a modeling protocol is discussed.