Research On Temperature Field And Thermally-Induced Vibration Of Large Space Hoop Truss Structures

Hoop truss is a major supporting structure of the space deployable cable-net antenna which has ultra compact folded size,light weight.After deployment,the structure is very large and flexible.When the hoop truss moves on orbit,especially it goes into/out the shadow area of the Earth,a sudden thermal load would give rise to structural deformation,thermally-induced vibration and so on.In general,it is very difficult and expensive to have the full-size experimental research on the ground.So,it is necessary to numerically simulate the temperature field and mechanical behavior for the hoop truss orbiting the Earth.First,the input-output heat flux data of each truss member from the solar radiation,earth infrared radiation,and earth albedo radiation are obtained,according to the on-orbital position of the truss members.The temperature field of the hoop truss on the geostationary orbit at the spring equinox is calculated by simulation,and then the temperature difference of the hoop truss on orbit is analyzed,which may induce the structural deformation and vibration problems.Second,based on the Fouier finite element method of temperature and structure finite element method,the dynamic response of a cantilever beam with tip mass under thermal shock is studied.Afterwards,for different kinds of materiasl,diameters,radius of cylindrical truss,wall thickness,the thermally-induced responses of a hoop truss with 12.5m diameter subjected to thermal shock are analyzed.Finally,based on the continuum model of a space beam and a space circular ring,the simplified approximate model for hoop truss is established,thereby the stable region for thermally-induced vibration is given.In this thesis,temperature field and thermally-induced vibration of the large space hoop truss are studied.The transient temperature field and the response of thermally induced vibration of this model are simulated.The proposed methods in the paper can provid references for the thermal design and the vibration suppression of the hoop truss.