The Research On Configuration And Analytical Method Of Torus-type Tensegrity Structures

In recent years,domestic and overseas are studying a new kind of space structure:tensegrity structure.Tensegrity structure has the advantages of light quality and high stiffness,therefore,it has became one of the forefront research direction in the field of space structure.Draw on the idea of tensegrity structure,cable dome has been designed and used in engineering,and foreign researchers are studying the developability of tensegrity structure and tensegrity robot.There are three main aspects on tensegrity structure's study:configuration research,statics research and dynamics research,therein configuration research,statics research are the basis of tensegrity structure's study,but there is no unified theory at present.This paper will lucubrate the configuration and statics of Torus-type Tensegrity Structures,specific research contents are as follows:Firstly,a series of Torus-type Tensegrity Structures will be designed.Based on “double spiral plane topology theory”,define the arrangement of nodes and the connection of bars(strings)between nodes,then get the node matrix and bar(string)connection matrix of Torus-type Tensegrity Structures,the specific shape of Torus-type Tensegrity Structure will be decided by four parameters: middle radius ‘R' and sectional radius ‘r' of torus,number of plies‘h' and number of nodes stay in every ply ‘k'.Take advantage of MATLAB software to conduct the virtual build of Torus-type Tensegrity Structures and choose one Torus-type Tensegrity Structure for model making.Secondly,parameter optimization should be done about the series of Torus-type Tensegrity Structures.On the basis of the bars of Torus-type Tensegrity Structures can't intersect and interference,and in view of torus fitting rate of Torus-type Tensegrity Structures,four parameters can be optimized then get multifold Torus-type Tensegrity Structures,and get the minsize of R(r)that make multifold Torus-type Tensegrity Structures' bars nonintervention,the quality of multi-minsize Torus-type Tensegrity Structures will be analyse,too.The following analysis is aim at optimized Torus-type Tensegrity Structures.Thirdly,a new stability and force analytical method of tensegrity structure will be studied,this method will be called as “Analytical Method of Remove Strings”.Based on stability and force analytical method of truss structure,after comparative study,present an assumption about how to analyse the stability and force of tensegrity structure,use thisassumption to analyse an example of Torus-type Tensegrity Structures,and get the analytical result,the effectiveness of “Analytical Method of Remove Strings” will be verified by ANSYS.Finally determine the carrying capacity of the example of Torus-type Tensegrity Structures by the analytical result.Last,a method about how to decide the prestressing value of strings will be studied,and prestress for multi-minsize Torus-type Tensegrity Structures,then make analysis and comparison about compressional stiffness of them.Based on Dynamic Relaxation Method used for analyse unstability of cable nets structure,deduce the analytical method that judging if Torus-type Tensegrity Structures can maintain it's shape,then choose two Torus-type Tensegrity Structures whose compressional stiffness are weaker,and judge the ability of maintain their shape.Through these studies,get the configuration and statics analytical process of Torus-type Tensegrity Structures,and estimate the potential used in practical engineering of Torus-type Tensegrity Structures.The methods studied in this paper can apply to other tensegrity structures,too.