The Mechanical Property Study On Spherical Mega Grid Structure Of Rib Ring With Semi-Rigid Joint

Some research results show that nodes in the most of space structure actually belong to semi-rigid joints between the hinge and rigid.Currently,some achievements have been obtained in the research of semi-rigid joints of conventional lattice shell at home and abroad, but few studies have been made on the semi-rigid joints of the new space mega grid structures. In this paper, the influence of joint stiffness on the mechanical properties of the space mega grid structure with ANSYS finite element analysis software are studied. The main research contents are as follows:(1) Two kinds of verification model with semi-rigid joints is established, and the correctness of the model is verified. Researching basic static performance of spherical mega grid structure of rib ring by considering axial stiffness and bending stiffness of joint at the same time.The influence of joint stiffness on the internal force and displacement of the structure under the normal temperature and different temperature is investigated. At the same time, the correlation parameters such as the ratio of rise to span, the truss beam height, the support condition and the local loading are analyzed. The results show that the joint stiffness has significant influence on the size and distribution of the internal force and the displacement of the joints.(2) Stability is the key problem in the design of conventional lattice shell structures. In this paper, the eigenvalue buckling analysis is performed on 3 kinds of spherical mega grid structure of rib ring with semi-rigid. At the same time, the eigenvalue buckling analysis of the correlation parameters such as the ratio of rise to span, the height of truss beam and the support condition of the structure with bidirectional semi-rigid joints is performed, And the influence coefficient of joint stiffness about eigenvalue is introduced to judge the influence degree of joint stiffness on the structure with semi-rigid joints. In addition, the nonlinear buckling analysis of 3 kinds of the structure with semi-rigid joints is carried out,also the load displacement curve and the ultimate stability bearing capacity of the structure are also obtained, by considering the geometric nonlinearity and initial imperfections. The results show that the the joint stiffness has significant influence on the static stability of the structure.(3) Analysis of the fundamental frequency and the formation graph of 3 kinds of the structure with semi-rigid joints, the internal force and displacement of 3 kinds of the structure with semi-rigid joints are obtained by elastic plastic time history analysis of the three dimensional rare earthquake. The results show that the joint stiffness has significant influence on the dynamic performance of the structure.