Mechanical properties of the hierarchical honeycombs with stochastic Voronoi sub-structuresYinghong Du, Nicola Pugno, Baoming Gong, Dongpo Wang, Yongtao Sun and Qian DingEPL, 111 5 (2015) 56007DOI: https://doi.org/10.1209/0295-5075/111/56007