Simulation And Optimization On Mechanical Properties Of Inflatable Sandwich Arrayed Structures

Compared with the traditional rigid deformable array structure,the inflatable sandwich array structure has the advantages of small volume,light weight,high storage and easy transportation.In order to ensure the require ments of lightweight design for large-scale deployable structures,and to increase the rigidity and strength of the array structure,This paper proposes a rigid-flexible coupling inflatable wing constructed with an inflatable sandwich array structure,That is,the design of the carbon fiber ribbed frame combined with the closed air chamber is used to replace the fully flexible material inflatable structure.There is currently no perfect theoretical basis to support this design plan,Therefore,this paper st udies the deformation characteristics,bending stiffness and static and dynamic characteristics of the inflatable sandwich array structure,and further optimizes the design of the size parameters.First,the nonlinear deformation of the inflatable sandwich thin-plate structure is analyzed when it swells,The quantitative relationship between the bulging deformation of the single cell of the sandwich thin plate and the center angle,the radius of the bulging circle and the spacing of the thin plates under inflation pressure is established;Establish the finite element model of the single cell of the inflatable sandwich thin plate,Discussion and analysis of the mechanical characteristics of the thin plate during the normal loading process,Fit the empirica l formula of inflation pressure and out-of-plane normal stiffness;Further study the theoretical solution and finite element simulation of the unit cell of the sandwich thin plate under bending loading mode,The influencing factors of bending deformation are determined,The effect of inflation pressure on bending stiffness is discussed.Secondly,taking the symmetrical five-sheet structure of the inflatable sandwich array structure as the research object,Established a finite element model of an inflatable sandwich array structure,Simulate the deformation process of the thin plate during bending and loading,Comparative analysis of the influence of inflation pressure on the bending stiffness of structures with different number of unit cells;The dynamic characteristics and transient response of the inflatable sandwich array structure are studied,Discuss the influence of inflation pressure,number of unit cells and boundary conditions on dynamic characteristics.Further studied the delta wing model of the inflatable sandwich array constructed in a fan-shaped manner,Through the above method,the mechanical and dynamic characteristics of the delta wing bending loading are simulated.And verify the finite element simulation model through experiments.Finally,the size parameters of the inflatable sandwich array structure are optimized.First,the OPTLHD method was used to efficiently sample the structure parameter space of the sandwich array.Taking the internal gas quality,bending stiffness and structural fundamental frequency as the objective function,The agent model of the objective function is constructed by using the RBF neural network model,And verified the accuracy of the proxy model,Finally,the NCGA algorithm was used to optimize the design of the model.The Pareto optimal solution set of the sandwich array structure is obtained,and the optimized sandwich array structure scheme is given.The results show that the mechanical properties of the optimized structure are significantly better than the initial scheme.