The Design And Analysis Of Truss Structure Mast

The space mast,the most basic space deployable structure,is a kind of folding and deployable mechanism.It becomes compact after being folded,which saves space and make storage and transportation easier.When it is unfolded,it has the big-scale work-need space shape.Unfolding the space mast is in the working state and required certain shape-preserving and load-carrying capacity,lots of space masts in the unfolded state are constructed by the truss structures frequently.So,in order to obtain design method of the similar truss structural masts,in this paper the space mast is constructed basing on octahedral truss units.Firstly,the structural design of the deployable truss mast is carried out through analyzing the octahedral truss unit.With the idea of the tensegrity,the initial design of the truss unit is obtained by reducing the mass of unit.To lay foundation for the overall design,its stability is analyzed and judged by the method of the force density.Secondly,the method of mechanizing the truss structure is researched through analyzing deployable theory of the octahedral truss mast,which determine the kinematic pair in the structure by knowing the node change and relative motion between the two bars.Then degree of freedom of the mechanism is computed further.With the ADAMS software of dynamics analysis,the model of truss including two octahedral truss units and motion process are simulated.Thirdly,the theory of topology analysis is used to obtain new mechanism basing on topological invariant of the mechanism.Compared the new mechanism and the old,we can obtain the good property one.Then in order to determine arrangement of strings in structure and reduce the controlling complexity,law for strings length change are analyzed and different change type strings are classified by computing the distance of two endpoint of strings.At last,with the method of the finite element,building model and static load of the octahedral truss mast are analyzed.Then to obtain the space mast better,the same and different cross section mast are compared in its stiffness and strength according to the theory of cantilever beam.