Research On Influence Of Telescopic Link On The Mechanical Properties Of Triangular-truss Articulated Mast

The triangular-truss articulated mast is a space deployable folding structure,which is widely used in large space deployable structures.The triangular-truss articulated mast is usually composed of longitudinal rods and transverse bars as well as telescopic levers,which is driven by a stepper motor to drive the extension arm.When the stretching mast is expanded,the telescopic lever is tightened under the preload,but when the vibration amplitude is large,the telescopic lever will relax,so it is necessary to study the effect of telescopic lever on the performance of stretching mast.In this paper,the influence of telescopic lever on the mechanical properties of articulated extension arm with three longitudinal rods is analyzed and studied.The main research work and conclusions in this paper as follow:(1)The finite element model of the articulated mast structure is established with Software which is used as a model-built tool;Study the tensile stiffness and torsional stiffness as well as flexural static stiffness of the extension arm in full expansion state;and analyze the influence of the size parameters of the telescopic link on the static stiffness of the extension arm.The following conclusions are drawn: Expanding the size of the rod will lead to the increase in the static stiffness of the extension arm,so,the telescopic rod size should be perfect in the case of meeting the structural requirements.(2)Using the Lanczos method and the Riks method to calculate the linear and nonlinear buckling critical load;the influence of the geometrical parameters of the telescopic lever on the buckling load of the extension arm is analyzed;and the effect of the preload of the telescopic link on the stability of the extension arm is studied.The following conclusions are drawn: The reduction of telescopic rod size can reduce the stability of the extension arm,and the proper size of the telescopic lever can increase the stability of the extension arm,and increase the preload of the telescopic lever to improve the stability of the extension arm.(3)The modal analysis of the stretching mast structure is studied,and the influence of the geometrical size of the telescopic pull rod on the modal and dynamic response of the extension arm is studied by using HHT calculation method.The following conclusions are drawn: The main deformation mode of the extensible mast is bending deformation;The size of telescopic rod increases,the velocity and acceleration response curve of the structure decreases.(4)The passive control scheme of the structure is given by combining the friction property of telescopic linkage.the maximum acceleration response of the extension arm is reduced by 30%,which provides a reliable basis and valid conclusion for the structure design of the extensional arm.