Study On Parametric Modeling Technology And Optimization Design Of Heterogeneous Honeycomb Structure

With the rapid development of social industry,The multifunctional requirements of the structure are becoming more and more stringent by modern industry.Honeycomb porous structures are widely used because of their excellent properties,while traditional honeycomb structures mostly focus on periodic arrangement or uniform distribution,and the potential properties of honeycomb structures cannot be fully exploited.In this paper,taking honeycomb structure as the research object,two design methods of heterogeneous honeycomb structure are proposed,based on parametric modeling technology,the modeling efficiency of heterogeneous honeycomb structure is improved.The mechanical response characteristics of two kinds of heterogeneous honeycomb structures were studied from out-of-plane and in-plane directions by using experimental techniques and numerical simulation methods.Combined with experimental design,surrogate model and multi-objective optimization algorithm,the optimization design research of heterogeneous honeycomb structure is carried out,which provides new ideas and methods for further exerting the lightweight and high-strength performance of honeycomb structure.The specific research contents are summarized as follows:(1)On the basis of the traditional homogeneous hexagonal honeycomb structure with equal wall thickness,two design ideas for heterogeneous honeycomb structures are proposed: the cell relative density changes along the direction gradient and the cell relative density is based on topology optimization density mapping.The geometric parameters of the honeycomb structure are analyzed,the theoretical basis and design ideas of the two kinds of heterogeneous honeycombs are expounded,and the modeling programs of the two kinds of heterogeneous honeycombs are written using the parametric modeling method combined with the secondary development of the Solid Works software.And generate executable files to realize the rapid establishment of geometric model of heterogeneous honeycomb structure.(2)Combined with experimental and finite element analysis methods,the effects of geometric parameters on the deformation mode,mechanical response and energy absorption characteristics of gradient density heterogeneous honeycomb structures under out-of-plane loading conditions are studied.The results show that under the out-of-plane quasi-static compression condition,the deformation mode of the gradient density heterogeneous honeycomb is similar to that of the ordinary honeycomb and is affected by the gradient coefficient.Heterogeneous honeycombs with a certain positive gradient can improve their out-of-plane stiffness and energy absorption properties.The gradient coefficient has little effect on the peak impact force of the honeycomb,while the cell size has a greater impact on the peak impact force of the honeycomb.Taking gradient coefficient and cell size as design variables,specific energy absorption and peak impact force as targets,a multi-objective optimization design was carried out based on Kriging model and NSGA-Ⅱ algorithm.The peak impact force of optimized gradient density heterogeneous honeycomb decreased by 43.79 k N,the specific energy absorption increased by 0.314 k J/kg,and a heterogeneous honeycomb with better comprehensive energy absorption characteristics is obtained.(3)The in-plane dynamic impact deformation mode,dynamic mechanical response and energy absorption characteristics of density-mapping heterogeneous honeycombs at different impact velocities are studied.The results show that the in-plane deformation mode of the mapping coefficient heterogeneous honeycomb is related to the mapping coefficient,relative density and impact velocity.The increase of the mapping coefficient,impact velocity and relative density will significantly increase the stress of the honeycomb platform.Reasonably changing the mapping coefficient and relative density can effectively improve the energy absorption capacity of the density-mapping heterogeneous honeycomb structure.The results of multi-objective optimization of density-mapping heterogeneous honeycomb based on the full factorial experimental design method and the response surface approximation model show that the peak impact force of the optimized mapping density heterogeneous honeycomb structure decreases by 12.6%,while the specific energy absorption increases by 21.6%,showing a better energy absorption performance improvement effect.