Study On Bending And Tensile Shear Properties Of Porous Honeycomb Stiffened Plates

With the rapid development of aerospace,engineering machinery,transportation,and other fields,load-bearing components are required to possess higher strength.This has prompted researchers to focus on exploring advanced structures.Laminated plate and shell structures,which are foundational structures in engineering,produce different responses when subjected to various external loads.Therefore,analyzing the failure modes of laminated plate structures under different loads is critical to enhance the structure and prevent hidden safety events in engineering.Porous honeycomb structures,which are considered one of the most promising advanced structures.This paper applies the excellent characteristics of the honeycomb structure to reinforce laminate plate structures,creating a porous honeycomb reinforced plate structure by combining honeycomb structure as a reinforcement layer and skin.The study methodology combines experimental testing and finite element simulation,and all test samples were prepared using 3D printing technology with PLA(polylactic acid fiber)as the sample material.This study primarily focuses on the bearing characteristics and deformation modes of porous honeycomb stiffened plates under different loads and optimizes the structure by exploring the topological configuration and layout.The main study content and conclusions are as follows:To begin with,the study focuses on analyzing the bearing characteristics and deformation modes of the structure under a three-point bending load.A model of a porous honeycomb stiffened plate is designed,which includes various geometric parameters such as porous configuration,arrangement direction,and pore angle.Through the testing and simulation of the structure,the results indicate that the structure exhibits typical bending deformation under a three-point bending load,with the failure mode occurring at the pore angle and spreading along the longitudinal cell wall.The study also explores the influence of different geometric parameters,revealing that the honeycomb configuration is superior to the orthogonal grid configuration.Moreover,the vertical arrangement of honeycomb configuration is found to be more favorable than other directions.Additionally,the structural load and energy absorption characteristics are stronger when the angle of honeycomb pores is smaller.Next,the structure is optimized in three aspects-pore boundary,cell layout,and mass distribution-based on the study findings from the previous section.The study introduces a optimization method that employs curve boundary and gradient layout.The wall thickness and porosity are used as gradient parameters,and two gradient layout models are designed based on the principle of structure and other quality.The results demonstrate that stress concentration can be effectively improved by designing the boundary of the pass as a curve.Additionally,the flexural performance of porous cells is notably enhanced after the gradient layout is implemented,particularly with the gradient layout of wall thickness.Moreover,to maximize material utilization,the conventional plane stiffened layer is designed as a curved surface stiffened layer,based on the main bearing position and stress form of the stiffened plate,and the energy absorption of both structures is evaluated.The results reveal that the specific energy absorption rate of the curved stiffened layer structure is significantly higher than that of the conventional structure,thereby improving material utilization efficiency.The study also examines the influence of the head position on the bearing capacity and deformation mode of the structure,revealing that the structure’s bearing capacity increases as the head position becomes more inclined,and the failure form of interlayer detachment appears after the inclined head position.Finally,the study examines the bearing characteristics and failure modes of the honeycomb stiffened plate under a tensile shear load.A square tension-shear model is designed to investigate the influence of honeycomb direction,honeycomb wall thickness,and skin thickness on the bearing characteristics and deformation mode.The results indicate that the structure exhibits a transient failure mode along the transverse direction at the central position under the tensile-shear load.Moreover,the optimal direction for the regular hexagonal honeycomb is 15°,while for negative Poisson’s ratio honeycomb,the optimal direction is 45°.Furthermore,increasing the honeycomb wall thickness and skin thickness helps to improve the bearing characteristics of the structure.