The Stability Analysis And The Dynamic Characteristics Analysis Of Self-Balanced Prestressed Spherical Surface Latticed Shell

Element combination form and self-balanced prestressed steel structure is a new spatial system composed by prestressed cable and strut elements. The element and the whole structure can keep balance themselves, no needing load-bearing structure or stiff annular beam. The stability analysis and the dynamic characteristics analysis of a super spherical surface latticed shell assembled by self-balanced prestressed structural units is presented.The structural unit is set up by several struts and flexible tension bars and obtained the space stiffness through prestressing.Total trend in development of latticed domes is that the span of latticed dome becomes more and more large, as well as the material used becomes more and more economic with the development of building materials, computer technique and structural theory. So, the stability is the key problem on the structural design of latticed domes. By using the large finite element software ANSYS, the buckling load and mode of structure is concluded with Block Lanczes, and then it is considered that the prestressing makes effects on the stability of the shell structure. In the calculation, it is considered that the effect of the shell structure which is made by the form of the loads and the geometric nonlinear factors of the structure.The influence of the structural stability due to initial disfigurement is studied with consistent imperfect buckling analysis method. The most disadvantaged geometric deficiencies are simulated by the buckling mode, and then the non-linear stability of the defective structure is analyzed. In order to improve the stability of the structure,the load-displacement curve will be listed, analyzing the eigenvalue buckling by using the large finite element software Ansys analyses. Then the critical point and critical load is determined by the load-displacement analysis of stability to this structure.In the dynamic analysis of the structure, self-balanced prestressed spherical surface latticed shell is also modal analyzed with subspace iteration method, by using the finite element software ANSYS. The vibration frequency and the modal shape are concluded by modal analyzed, and then the differences of the vibration frequency are compared under different prestressing values. The changes in the vibration frequency and the modal shape are considered when the structure is influnced by the external load.