Dynamic Modeling and Analysis of Cable-Strut Deployable Articulated Mast

A rational modeling method based on energy equivalence principle is presented for developing an equivalent dynamic continuum beam model of cable-strut deployable articulated mast according to the structural characteristics of the mast.A basic truss bay of the mast is isolated,and its strain and kinetic energies expression in terms of nodal displacement,geometrical structure and material parameters of the truss bay are derived.The relationship of geometrical structure and material parameters between the mast truss structure and the equivalent continuum beam model is established based on strain and kinetic energies equivalence principle between the mast truss bay and the continuum beam model,the equivalent stiffness matrix and mass matrix of equivalent continuum beam model are derived.Equivalent stiffness and mass parameters of the mast principle prototype are calculated by using equivalent continuum beam modeling method of the cable-strut deployable articulated mast.Dynamics of the mast is analyzed based on the equivalent continuum model and the finite element model,first eight natural frequencies of the mast are obtained through theoretical calculation and simulation.The equivalent continuum beam model of the mast is verified through comparison between simulation results of the finite element model and theoretical calculation results of the equivalent model.It is concluded that the equivalent continuum beam model is more accurate to analyze dynamics of long cable-strut deployable articulated mast through natural frequencies comparison of masts with different length.