Radar Skeleton Deformation Theory And Simulation Research Based On Pretightening Force

As an important part of radar, the antenna’s support frame will achieve structural deformation under the effect of weight and external load, which will affect the antenna array’s surface flatness, so that it will directly affect the antenna’s electrical performance. The radar antenna structure which has been studied in this paper belongs to the series of automatic expand and collapse, each module respectively under the action of their four bar mechanism to achieve auto-outspread/auto-fold, under the action of sensor to achieve positioning, under the action of positioning pin/hole and positioning claw to achieve position limit, and then continue driving the screw nut move which will produce pre-tightening force to keep antenna structure locking. The role of pre-tightening force is to ensure that the antenna has some structure stiffness while the antenna’s is unfolding, meanwhile, the deformation of antenna in work should be in the scope of the accuracy requirement.The article is supported by an enterprise technology research project, with the finite element analysis and the theory of multi-body dynamics as the foundation. On the perspective of structural optimization,build the dynamics mathematical modeling for the skeleton’s deployable mechanism of a parabolic radar antenna, and then do finite element simulation analysis and multi-body dynamics simulation analysis; Research the relationship between pre-tightening force, location layout and radar antenna skeleton’s deformation, and ensure antenna array surface precision and stress achieve the best state.This article main research content is as follows:(1) Based on the analysis of the characteristics of the radar skeleton automatic unfolding and folding driving mechanism, make kinematic analysis for the organization; Find out the formation of pre-tightening force and the action mechanism; Construct the dynamics model of the antenna frame deployable mechanism; Find the key factors affecting radar antenna skeleton’s deformation. And use Pro/E software to establish radar antenna frame’s 3D model.(2) In the ADAMS simulation model if considering the influence of the flexible parts, it will greatly improve the accuracy of the simulation results. Alone in the finite element software to establish screw model, generate the modal neutral file and then import to ADAMS to substitute the original rigid body, and finally generate firm soft hybrid model.(3)Using multi-body dynamics simulation software ADAMS to do simulation for the established firm soft hybrid model, Through the simulation of antenna’s movement, get radar skeleton’s driving force curve in the process of the Deployable structure work; meanwhile, do Parametric modeling for the positioning claw, obtain the corresponding positioning mechanism’s contact stress changes by simulation.(4) Using ANSYS’s dynamic simulation module, According to the principle of unfolding principle and pre-tightening principle to apply load, get the relationship between the pre-tightening force and the antenna deformation; Then add the wind load, wind load can be apply in the form of load step, simulate different levels of wind speed. Through the finite element analysis, we can get the skeleton’s resistance to wind load after the preloaded.This article’s research work verified the rationality of the positioning layout, studied the influence of the radar antenna skeleton pre-tightening force and positioning claw’s location layout on skeleton deformation, which is from the two perspectives of structural optimization and pre-tightening force control, studied how to ensure antenna array surface precision while it’s in work and its stress achieve the best state.Provide design basis for the subsequent product’s development.