Analytical model and energy harvesting analysis of a vibrating slender rod with added tip mass in three-dimensional spaceMarek Borowiec, Marcin Bochenski, Grzegorz Litak and Andrzej TeterEur. Phys. J. Spec. Top., 230 18-20 (2021) 3581-3590DOI: https://doi.org/10.1140/epjs/s11734-021-00241-7