Hydrostatic stress and triaxiality factors in a lotus root cross section

Engineers often use nature as an inspiration for generating designs. Plants have optimised their structures over millions of years of evolution. A lotus root, rhizome of Nelumbo Nucifera Gaertn having gas canals was studied in the paper. The lotus root cross section subjected to an external water pressure was analysed and compared with other cross sections including a circular hollow cross section. It was found that the lotus root cross section has more areas containing higher triaxiality factors due to the holes. The hydrostatic stress in the lotus root cross section varies from zero to several times that of the external water pressure. However, the hydrostatic stress in a circular hollow cross section has a constant ratio to the external pressure. The research results show that engineering components with designed multi-holes can affect its failure behaviour. The structure of lotus root may be adopted in the design of engineering materials and structures.