Study On Geometric Configuration And Mechanical Properties Of Deployable Cylindrical Shells With Reciprocal Support

Deployable structure is a new type of space structure developed in the 1960 s to solve the problem of space occupation.Deployable structure is widely used in aerospace,machinery,medicine,architecture and civil engineering and other fields.This paper focuses on the study of deployable cylindrical shells with reciprocal support.The structure adopts the mutual bearing lap joint,and the components of the expanded column shell support each other at the joint,forming a self-locking stable structure.Deployable cylindrical shells with reciprocal support has the advantages of both deployable structure and reciprocal structure: simple structure,lightweight and compact,reusable,easy to store and transport.In this paper,the geometric configuration and folding process,joint structure and properties,static mechanical properties and static stability of deployable cylindrical shells with reciprocal support are studied.The specific contents are as follows:(1)In view of the geometric configuration and folding problems of deployable cylindrical shells with reciprocal support,the geometric conditions satisfying the folding and development requirements of deployable cylindrical shells with reciprocal support and the demands of reciprocal lapping between the rods were formed by summarizing the literature,and the basic formulas for the folding and folding of deployable cylindrical shells with reciprocal support and joint lapping of joint rods were given.A deployable cylindrical shells with reciprocal support configuration generating module is designed to generate different shapes of folding column shells according to the change of geometric parameters.The simulation of folding and developing process of deployable cylindrical shells with reciprocal support is carried out to verify the correctness of geometric conditions for forming deployable cylindrical shells with reciprocal support.(2)According to the joint lap characteristics of deployable cylindrical shells with reciprocal support,a new type of joint with reciprocal fastener was developed.Considering the two boundary conditions of the bar bottom fixed and hinged connection,the vertical displacement load is applied step by step to the joint,and the ultimate bearing capacity test of the joint is carried out:The joint is weak at the fastener bolt,and the joint is destroyed by cutting the fastener bolt in the test.The maximum bearing capacity of the specimens with solid connection at the bottom of the reciprocal member is greater than that of the specimens with hinged connection at the bottom.The finite element software is used to simulate the results.The results show that the test is in good agreement with the finite element results.(3)The static property of the structure is analyzed by ANSYS finite element software.By comparing the static properties of rigid and hinged deployable column shells,the analysis shows that the axial force,shear force and bending moment coexist in the bar,and the stress situation is more complicated.The maximum vertical displacement,maximum axial force and maximum strain energy are smaller,the stress distribution is more uniform,and the stiffness is greater for the rigid lap joint deployable cylindrical shells.It is found that the maximum vertical displacement,maximum axial force and maximum strain energy of column shell decrease first and then increase with the increase of shell thickness.With the increase of the number of grids,the maximum vertical displacement,maximum axial force and maximum strain energy of the column shell decreased,the stiffness of the column shell increased,and the stress distribution became more uniform.(4)Using ANSYS finite element software to analyze the static stability of the structure,including linear buckling analysis and nonlinear stability analysis.The effects of geometric parameters on static stability were analyzed.The results show that: under vertical full span load and vertical half span load,the characteristic values of each order increase with the increase of shell thickness and mesh number,and the stability of column shell is constantly improved.Through nonlinear analysis,it is found that with the increase of column shell thickness and mesh number,column shell stiffness,stability and ultimate bearing capacity increase.