Energy Absorption Characteristics And High G Protection Research Of Leaf Vein Multi-cell Thin-walled Structure

The impact energy absorption performance of the structure under extreme loads such as impact and explosion are very important for its safety performance.Thin-walled structures are widely used in shock-resistant design and energy-absorbing devices because of their light weight,high specific energy absorption and stable and controllable crushing load.Inspired by the veins of leaves,this paper designs several new structural forms with excellent performance on the basis of multi-cell tubes.Quasi-static compression experiments were carried out on samples prepared by 3D printing technology,and their deformation modes and energy absorption characteristics were analyzed.Based on the simulation results,these structures were designed with multi-objective optimization,and then the theoretical model of their average crushing force was predicted with the theory of super-folding element.The specific research contents are as follows: The main results are as follows:(1)A new type of energy absorption device is proposed based on the common multi-cell tube and parallel vein structure.The finite element technology is used to simulate the bionic multi-cell tube under axial compression and impact,and its energy absorption characteristics are studied.Based on experiments and numerical simulation,the effects of tube wall thickness,secondary rib shape and impact speed on structural deformation and energy absorption are studied,and the enhancement mechanism of secondary rib on energy absorption of multi-cell tube is analyzed.Compared with the traditional multi-cell tube,the study shows that the overall energy absorption efficiency of bionic thin-walled tube is significantly higher than that of the corresponding common multi-cell tube,and the deformation mode under axial collapse can be induced and improved.(2)Based on reticulated veins,a new structure is proposed to improve the energy absorption characteristics of multi-cell tubes.The deformation mode is changed by controlling and changing the cross-sectional shape of the bionic multi-cell tube under axial compression.The research results show that the four pattern types introduced in this paper have achieved the expected effect,significantly improving and improving the energy absorption characteristics of the bionic multi-cell tube.Finally,the structural optimization design is carried out for its wall thickness and internal distance.(3)Based on the simplified super-folding element theory,the average crushing force of regularly folded bionic multi-cell tube under axial compression is analyzed.Considering the energy dissipated in compression,the prediction formula of the average crushing force of bionic multi-cell tube is derived.Through comparative analysis,it is found that the numerical simulation results are in good agreement with the theoretical prediction results of the average crushing force,so the theoretical prediction model has enough accuracy to predict the average crushing force.(4)Firstly,the experimental equipment and process of high G-value impact response are introduced,and the high G-value impact experiment of multi-cell tube is carried out,which is verified by numerical method,and the influence of different structures and impact velocity is analyzed.Finally,the polynomial Response surface mode is used to construct the proxy model of response acceleration and energy absorption,and the PRSM model is used to establish an approximate model.The effects of different wall thickness and impact velocity of different structures on the response acceleration and energy absorption of the structure are analyzed.