Study On The Mechanical Properties Of Honeycomb With Holes On The Wall And Its Hierarchical Structure

Honeycomb sandwich panel structures have high specific strength,high specific stiffness and excellent compression resistance,which can be widely used as energy absorbing materials in transportation,packaging,wind power generation and other fields.Therefore,this paper studies the numerical simulation of honeycomb with holes on the wall and its hierarchical structure,the main contents are as follows:(1)In order to study the average compressive stress of honeycomb with holes in the wall under quasi-static out of plane compression,based on the energy principle,the calculation formula of the average compressive stress of honeycomb with holes in the wall is derived with the "Y" cell as the research object.Through the establishment of finite element models with different hole to edge ratios,the influence factors of the extended area in the formula of average compressive stress are studied.When the scale factor is 1,the influence factors of the extended area are linearly related to the hole to edge ratio.Through the numerical calculation of the average compressive stress of the honeycomb with different thickness to edge ratio,the accuracy of the theoretical formula is verified,and the influence of the hole shape and scale factor on the average compressive stress is discussed.The results show that the average compressive stress of the honeycomb structure with holes in the wall is mainly affected by the change of the strands and the extension area.The average compressive stress decreases with the increase of the ratio of the holes to the sides.When the scale factor increases,the extension area will decrease.Compared with the scale factor of 1,when the scale factor increases to make the compression process more stable,the average compressive stress will decrease about 40%.(2)The first five order finite element model of multi-layer honeycomb with holes in the wall is established,and its out of plane compression is simulated.The effects of relative density and order on the compression deformation mode,compression force and energy absorption of self similar honeycomb structures with holes in the wall are discussed.Self similar layer design can significantly improve the compression performance of honeycomb structure with holes in the wall.The deformation of low-order honeycomb with self similar wall openings is more uniform and the folding process is more stable.In the process of high-order honeycomb compression with holes in the wall,it is easy to be concave and convex,broken and collapsed.The compression force and energy absorption performance of the first to the fourth stage wall opening self similar level honeycomb out of the plane platform increased greatly compared with the ordinary hexagonal honeycomb(the zero stage),at the same time,the peak compression force also decreased to a certain extent.(3)The honeycomb with holes on the wall is designed in a non self phase hierarchical way.The effects of wall thickness and hole edge ratio on the compression deformation mode,compression force and energy absorption of honeycomb structures with different orders of wall opening are studied,and the mechanical properties of different orders of wall opening are compared.The results show that the load efficiency of higher-order wall opening is higher than that of lower-order wall opening,and the energy absorption performance of higher-order wall opening is higher than that of lower-order wall opening.The value of the honeycomb with the same parameters is higher than that with the same parameters,and the standard deviation of the honeycomb with different parameters and wall thickness is much lower than that with the same parameters(except ?=0.3,t=0.1mm).In this paper,through the research of honeycomb structure with wall opening design and hierarchical optimization design,the conclusion has important practical significance and guiding value for the development and design of sandwich panel.