The Analysis Of Tensegrity Prism Structure

Tensegrity structure is a kind of special tensioning truss structure that is composed of compressive bar and tension cable, the component of the structure only carry axial load and this unique way of force distribution in makes the quality of tensegrity structures decrease significantly. In recent years it has became a research hotspot in the field of sculpture,architecture, aviation, etc. At present, the study of tensegrity structures are mainly concentrated in form-finding, equilibrium conditions and dynamics research, the study of the basic prism unit structure has not yet formed a unified theory. This article will take with the basic unit prism structure as the research object, and the related issues of tensegrity structure will be studied.For the configuration problem of tensegrity prism unit structure, the mathematical model of the structure will be established according to the geometrical parameters of the prismatic structure, and the relationship between the parameters and the position of the nodes, the node vector matrix and relationship of nodes and components will be determined. On the basis of connection matrix and member matrix, mathematical model of prismatic structure that described by the variable parameters will be established. By changing the cross-sectional radius of prism structure, it will transform to bevel structure.In view of the prism structure stability problems, the force balance equation of structure will be established in accordance with the mathematical model of tensegrity structure. The structure’s classification will be determined by using the singular value decomposition method to analysis of the balance matrix of system. The criteria for stability of tensegrity structure will get from the mobility of mechanisms and state of self-stress. At the same time,the introduction of component force density will help determine the force relationship between the components in the prism structure, and the stiffness matrix of the tensegrity structure (prestressed structure) will be completed. Rigidity and stability of structure will be verified by analyzing the prism structures.The characteristics of components of tensegrity structures that only bear of axial force make it possible to design minimum quality scheme. By distributing the load of structure to the node,the optimization model will be established and the minimum mass can be calculated.The mass analysis will consider buckling and yielding stress state, because compressive bar under the external force may be bent. Taking tensegrity prism as an example, the relationship between the length of the structure, power density and structural parameters member will be analyzed, to solve the structure of the yield at minimum mass limits, verify the correctness of the theory of minimum quality.Complex tensegrity structures are composed of simple unit structure, some kinds of can be get through the tensegrity prism unit structure’s topology combination, such as cylindrical structure, ring structure, double prism unit and cutting angle prism and so on. Combination of prism structures along the axial direction, resulting cylindrical structure, by changing its radial cross-section, different cylindrical structural will be obtained. Bending deformation of the cylindrical structure, the ring-type structure obtained by controlling the distribution of nodes,to obtain Different shapes of the ring structure will be obtained by bending cylindrical structure and controlling the distribution of nodes. The use of prismatic structure symmetrical composition, has been overcome its easy to reverse, obtaining two-cell prismatic structure.Truncated prism structures can be established by mixing a combination of prism and bevel unit structure.