Mechanism And Model Characterization Of In-plane Loading And Out-of-plane Bending Of Honeycomb Paperboard

Honeycomb paperboard materials are characterized by light weight,high energy absorption and good environmental protection.In recent years,the in-plane loading and bending properties are the key factors in the applications of transport package and construction.The stress and deformation of honeycomb paper core and facial tissue are quite complex in in-plane compression and out-of-plane bending.The deformation mechanism and the characterization of its bearing strength are the basis.Therefore,it is of important engineering value to study the theoretical and engineering applications of in-plane compression and out-of-plane bending of honeycomb paperboard.In this paper,the static mechanical behavior of honeycomb paperboard packaging under logistics environment is considered,researched the in-plane static compression mechanism,the out-of-plane bending bearing mechanism,bearing model characterization of honeycomb paperboard and an innovative design of honeycomb core layer structure had been carried out.Establishment of honeycomb paper board inner bearing and out of plane bending theory innovation model,and designed a new reinforced honeycomb core structure.The main research work was as follows:(1)In-plane loading mechanism and performance impact analysis of honeycomb paperboard.Based on in-plane load-bearing tests of honeycomb paperboard with different material parameters and structural parameters,the in-plane load-bearing mechanism was analyzed.On this basis,the influence factors of in-plane load-bearing strength of honeycomb paperboard were evaluated by grey relational entropy theory,and the primary and secondary relations and influence degree of the influence of surface paper quantity,honeycomb aperture and cardboard thickness on load-bearing performance were obtained.The results show that the buckling of the core layer and the surface layer presents different regularity in the longitudinal and transverse loads,and the longitudinal compression is mainly carried by the oblique single wall and the surface layer,while the transverse compression is mainly carried by the double cell wall,the single cell wall and the surface layer.The performance of honeycomb paperboard and the thickness of paperboard have great influence on the elastic modulus of honeycomb paperboard,and the performance of paperboard,the aperture size and the thickness of paperboard have significant influence on the platform stress and maximum absorbed energy.(2)Theoretical characterization of in-plane load-carrying strength of honeycomb paperboard.On the basis of in-plane load-bearing mechanism and performance analysis of honeycomb cardboard,a theoretical model of platform stress in the direction of vertical and horizontal load-bearing is established by using plastic deformation,plastic energy dissipation and energy conservation.On this basis,combined with the practical application of honeycomb cardboard,the in-plane longitudinal and transverse edge pressure strength of honeycomb cardboard was deduced.The in-plane plateau stress and edge pressure strength of honeycomb paperboard can be obtained by knowing the vertical and horizontal yield strength of base paper and material's "aperture edge length","core layer thickness","surface layer thickness" and "core layer base paper thickness".The comparison between theoretical values and experimental datas show that the model is in good agreement with each other.(3)Theoretical characterization of out-of-plane bending behavior of honeycomb cardboard beams.The analysis of out-of-plane flexural load-bearing elasticity,buckling and collapse deformation mechanism shows that the bending stiffness and ultimate bending load increase with the increase of cardboard thickness and decrease with the increase of aperture,while the maximum bending deflection decreases with the increase of cardboard thickness and increases with the increase of aperture.Based on the classical beam theory and the structure and material parameters of honeycomb paperboard,the longitudinal and transverse bending stiffness,ultimate bending load and maximum bending deflection of honeycomb paperboard were analyzed.The characterization equations of bending stiffness,ultimate bending load and maximum bending deflection of honeycomb paperboard three-point bending beams in longitudinal and transverse directions were obtained.The longitudinal and transverse elastic modulus of base paper and the material's "aperture edge length"," The bending stiffness,ultimate bending load and maximum bending deflection of honeycomb cardboard can be calculated by the thickness of the layer and the thickness of the core base paper.The results are in good agreement with the experimental data,which verifies the accuracy of the model.(4)Research on innovative design and performance characterization of honeycomb paperboard.A kind of reinforced honeycomb core structure was designed,and the bonding dimension and manufacturing process were designed.The mechanism of quasi-static compression deformation outside the surface of reinforced honeycomb cardboard was analyzed by experiments.Under the parameters of core size,the bearing strength of the reinforced honeycomb core structure was increased by 4 times on average.Under the same compressive strength,the reinforced structure could reduce the performance of honeycomb core material.The difficulty of production stretching is reduced by calculating or enlarging the aperture size.The comparison between theoretical and experimental data shows that the coincidence is high and the relative error is less than 11%.