Analysis And Research On Key Technologies Of Space Payload Connection Structure

With the continuous development of deep space exploration technology,space payloads have been deeply studied and widely used.As the weakest component in the whole,the connection structure of spacecraft is a key factor affecting the success of the design.In order to improve the reliability of space payloads.In this paper,with strength analysis as the main research objective,the key technologies of three typical connection structures are studied.1.Research on the bearing mechanical properties of the carbon fiber composite connection structure of the space payload bearing cylinder.Firstly,based on the theory of progressive damage and failure,a finite element analysis model of composite laminates was established.Secondly,the UMAT subroutine was developed using Fortran language according to the composite material damage and failure criteria—Hashin criterion and Tserpes material performance degradation criterion.The simulation analysis of the bolted connection of composite laminates of bearing cylinders and the mixed connection of glue and screw was carried out,and the failure mechanism of the connection structure under the two connection methods was studied.Finally,the stiffness of the connection structure,the extrusion damage of the bolt hole and the failure of the adhesive layer were analyzed in detail.The bolt connection structure stiffness obtained by simulation analysis was used to establish the bearing cylinder test piece model,and the finite element analysis and mechanical tests were carried out on the bearing cylinder to verify the validity and accuracy of the proposed method.The results showed that the application of the connection stiffness to the finite element analysis results of the Bush element instead of the MPC element to simulate the bolts,compared with the test results,the error was reduced by 4%?9%.This research provides a reference for the mechanical properties of the space payload composite bearing cylinder connection structure and the finite element analysis of the multi-bolt connection structure.2.The force distribution of bolt group and the thickness of the support plate of the space payload spaceborne connector are optimized.A joint optimization method is proposed.First,a free-size optimization mathematical model with the variance of the bolt axial force as the objective function is established to optimize the force of the bolt group;Secondly,on the basis of this model,the size of the support plate thickness of the spaceborne connector was optimized.The results show that through the proposed optimization method,the bolt axial force is reduced by 17.8% to 37.2%,and the fundamental frequency of the spaceborne adapter is effectively improved.3.The bonding performance of truss connection joints is studied.Firstly,a new type of TC4 truss glued joint was designed.Secondly,the influence of the adhesive strength of the connection area,the thickness of the adhesive layer and the modeling method on the failure load was analyzed by the finite element technique.Finally,through the analysis of the connection joint mechanical tests have verified the feasibility of the design and the effectiveness of the modeling method,which provides strong support for the design analysis of the truss joints and the rationalized modeling of the adhesive layer.