Effect Of Paper Dot Matrix Thin-wall Structure Defects On Its Mechanical Properties

Lattice-type thin-walled structural materials exist widely in nature,and honeycomb and corrugated sandwich structure materials are the most typical lattice-type materials currently used.Different defects will be produced during the production and use of lattice materials,and the defects will directly affect the strength of the lattice materials,thereby affecting the performance of lattice engineering structures or products.Therefore,studying the influence of defects of lattice materials on their mechanical properties is a problem that must be solved in order to use lattice materials reasonably.In this paper,the effects of defects on the mechanical properties of corrugated board and honeycomb board are studied by the method of experiment and numerical simulation.The research results are helpful to understand and make use of the thin-walled materials more comprehensively.The physical properties of corrugated and honeycomb paperboard base paper are tested.The results show that the value of the longitudinal elastic modulus of the base paper is larger than its transverse value.Therefore,the orthogonal anisotropy should be considered in the parameter model selection of the base paper.In this paper,the static compression experiments of honeycomb and corrugated board with different pore size defects are carried out,and the influence of different pore size defects on the horizontal and lateral compression strength of corrugated board and corrugated board is obtained.The results show that the sensitivity of honeycomb paperboard to open hole defects is less than that of corrugated paperboard,and the influence of open hole defects on the flat compression strength of corrugated paperboard and honeycomb paperboard is less than that on the side compression strength.The paperboard model with different defects was constructed by finite element simulation technology,and the numerical simulation of the load capacity experiment was carried out by the nonlinear analysis method,and the compression deformation map and stress cloud map of corrugated paperboard and honeycomb paperboard were obtained.The numerical simulation results are basically consistent with the experimental results,verifying the correctness of the experiment,and the critical dimensions of the opening defects of corrugated cardboard and honeycomb cardboard are 10 mm and 15 mm,respectively.The research results can provide corresponding basis for the size design of hand holes,vent holes or observation holes of honeycomb carton,corrugated carton.Based on the buckling criterion,the buckling analysis of the edge defect and the edge reinforcement model of the same scale corrugated board and honeycomb board was carried out by using the numerical simulation method.Using the same material,the same thickness and the same equivalent density,the finite element models of corrugated cardboard and honeycomb cardboard are constructed;the lateral compressive strength of the two cardboard models in CD direction is calculated and analyzed respectively;the edge enhancement models of the two structures are studied by taking measures to restrain the edge effect.The results show that the edge defect effect is one of the main factors affecting the lateral compressive strength of point matrix materials.