Elastoplastic Mechanical Analysis Of Rectangular Honeycomb Structure And Related Experimental Research

Porous materials are composed of closed or interpenetrating pores,and their advantages such as high specific strength,high specific stiffness,good heat insulation and shock resistance make them widely used in construction,cargo transportation,medical treatment,automobiles,ships,machinery and other fields.In terms of application,researchers have always been committed to studying its mechanical behavior under heat and load.In this paper,the application of the energy method in the calculation and analysis of structural equivalent mechanical properties is studied,and a series of studies are carried out on the elastoplastic model of the honeycomb structure.A rectangular honeycomb structure was studied.First,the relative density is calculated by establishing the geometric model of the structure,and the equivalent displacement of the structure under load is obtained by the energy method,so as to obtain the equivalent mechanical properties of the honeycomb structure.The wall plate and strut in the representative cell of the honeycomb structure are regarded as the beam under the combined action of axial force,shear force and bending moment under load,the basic method of structural mechanics is used to simplify and calculate the internal force equation of the cell,and the energy method is applied Obtain the equivalent displacement of the structure cell,and then calculate the equivalent strain,equivalent Young’s modulus and equivalent Poisson’s ratio of the structure according to the equivalent displacement and equivalent stress.Secondly,the plastic analysis of the structure is carried out according to the plastic hinge theory.When the load reaches a critical value,a plastic hinge will appear in the structure,and the plastic hinge will produce angular displacement without providing additional bending moment when the load continues to increase.Then,the theoretical model is verified by numerical simulation method and experimental method.The finite element model of rectangular honeycomb structure is established by using large-scale general-purpose finite element software,and the stress-strain relationship of the structure is obtained by controlling the boundary and load of the model,and the simulation results are compared with the theoretical results.Several rectangular honeycomb structures of PMMA materials were prepared,and the quasi-static tensile test was carried out through the hydraulic tensile test device.The experimental value of the equivalent mechanical performance could be obtained by using the experimental method,and the experimental value was compared with the theoretical value.Finally,through parameter analysis,the influence of each parameter on the mechanical properties of the structure is summarized and its laws are summarized.Several reinforced rectangular honeycomb structures are investigated.Add cross-connected rods to the rectangular honeycomb structure to obtain an X-shaped rod-reinforced rectangular honeycomb structure,and add cross-connected springs to the rectangular honeycomb structure to obtain a cross spring-reinforced rectangular honeycomb structure.The theoretical model of the reinforced rectangular honeycomb structure is established,the internal force equation of the structure is calculated and the structural displacement is calculated by the energy method,and the equivalent mechanical performance parameters of the structure are calculated.Some structures cannot solve the support reaction force and structural axial force through the balance equation when calculating the structural bending moment equation.The X-shaped member-reinforced rectangular honeycomb structure is such a structure,so this paper provides a general solution for this type of structure train of thought.When analyzing the cross spring-reinforced rectangular honeycomb structure,it is assumed that the elastic force of the spring is known and the equivalent displacement of the structure is obtained by decoupling the displacement equation.The research found that:the two reinforced structures can improve the equivalent Young’s modulus of the structure,and the reinforcement of the X-shaped rod is particularly obvious;the addition of the X-shaped rod reduces the equivalent Poisson’s ratio of the honeycomb structure,while the cross spring causes the equivalent The change in the effective Poisson’s ratio is very limited.