Research On Mechanical Characteristics Of Inflatable Flexible Drag Structure

The inflatable flexible resistance-increasing structure has the advantages of light weight,small folding volume,large deployment area,and low surface heat flux.This kind of utilization provides aerodynamic resistance for the flexible resistance surface that is actively deployed outside the atmosphere to provide emergency resistance for space materials and astronauts.Return and the entry of slow-moving spacecraft provide new technical solutions.When the pneumatic flexible resistance-increasing structure provides aerodynamic resistance for the payload,the flexible resistance-increasing structure undergoes deformation under the action of aerodynamic forces,which causes the aerodynamic shape of the structure to change,forming a gas-soft coupling effect,and when the dynamic pressure is too large,the flexibility The resistance-increasing structure will collapse and collapse.Therefore,the ability of the stacking ring structure to resist the deformation of the external load and the determination of the destabilizing load are the main problems in the study of the flexible resistance-increasing structure.In this paper,the theoretical model and numerical calculation methods are used to study the influence of the geometric parameters of the single inflatable ring and the stacked inflatable ring and the internal pressure of the inflatable on the structural instability load and the structural stiffness.Firstly,the stress distribution of the inflatable ring is analyzed using the momentless theory,and the deformation of the inflatable ring under the action of the inflation pressure is obtained;The critical load and the ultimate load are analyzed.The influences of the factors such as the internal pressure and geometric parameters on the critical load and ultimate load are discussed.Based on the theory of conservation of energy,the effect of uniform centripetal load on the inflated ring is given.The relationship between structural stiffness and structural parameters at the time,and using finite element to verify the derivation results.Secondly,based on the results of uniform in-plane load analysis of a single inflatable ring,the stress distribution of the double-layer stacking ring is further studied,and the ultimate load when the double-layered stacking ring is subjected to uniformly distributed centripetal loads in the plane is obtained.The influence of various parameters on the limit load of a double-layer stacking ring;the introduction of a stacking ring structure to resist the in-plane load efficiency,the stacking ring structure is optimized for design,and the limit load and structural rigidity of the structure subjected to external loads are increased.Finally,based on the standard k-? model,a gas-flexible coupling model of an inflatable flexible drag-enhanced structure was established,and the distribution of the flow field around the flexible drag-enhanced structure and the pressure distribution on the surface of the structure were analyzed under different inflow velocity and angle of attack.In this case,the characteristics of the deformation of the stacked ring structure with equal section diameter and variable cross-section diameter under the effect of inflow are compared and analyzed.The research results can provide the basis for the design of inflatable flexible resistive structures.