Saxena, RakeshSingh, Rakesh Kumar2021-03-172021-03-172021-02https://krishikosh.egranth.ac.in/handle/1/5810162495Honeycomb structures are stiff and light weight composite structures which show good energy absorption. Hierarchical honeycombs which are bio-inspired innovative form of honeycomb, are used for energy absorption applications. Sub-structure geometry affects the crashworthiness of hierarchical honeycombs. In the present investigation, crushing of vertex based hierarchical honeycomb with regular polygonal (n=3,6,9,12,15) and circular sub-structures is using non linear explicit finite element code LS-DYNA in both in-plane and out of plane direction crushing. Effect of different sub-structure geometry on crashworthiness of vertex based hierarchical honeycomb is studied. Further a parametric analysis is performed to investigate the effect of sub-structure size on crashworthiness of hierarchical honeycombs, for each sub-structure’s geometry. To investigate the effect of crushing velocity on energy absorption similar analyses are performed at higher crushing velocity. In case of in-plane crushing, vertex based hierarchical honeycomb with large sized triangular sub-structure is found to have best energy absorption compared to other hierarchical honeycombs. While in case of out of plane crushing, vertex based hierarchical honeycomb with small sized hexagonal sub-structure is found to have better energy absorption among compared to other hierarchical honeycombs. An improvement in energy absorption of hierarchical honeycombs is found in both in-plane and out of plane crushing at higher crushing velocity.EnglishThesis