Analysis On Thermally Induced Vibration And Dynamic Stiffness Of Cable-beam Structures

Cable-beam structures characterized by variable stiffness nonlinearities are widelyfound in various structural engineering applications, for example in space deployablestructures. Space deployable structures in orbit experience both high temperature causedby sun’s radiation and low temperature by Earth’s umbral shadow. The spacetemperature difference is above300K at the moment of exiting or entering Earth’sumbral shadow, which results in structural thermally induced vibration.To understand the thermally induced oscillations, the analytical expression ofBoley parameter of cable-beam structures is firstly deduced through the characteristicthermal time as well as the characteristic stucture time. Then, the transient heatconduction equation and the thermally induced vibration equation of cable-beamstructures is analyzed using finite element method to verify the effectiveness of Boleyparameter. Finally, by analyzing the obtained numerical results and the correspondingBoley parameters, it can be concluded that the derived expression of Boley parameter isvalid to evaluate the occurrence conditions of thermally induced vibration ofcable-beam structures and the key parameters influencing structural thermal flutter arethe cable stiffness and thickness of beams.The vibration resistance of cable-beam structures, namely the dynamic stiffness isdiscussed in the second part of this article. The analytical expressions of dynamicstiffnesses for the single-degree-of-freedom systern and the multi-degree-of-freedomsystem are firstly derived. Then, some aircraft actuator is taken as an example, and thedynamic stiffness of its spring mass sysmtem is calculated. Finally, through thethermal-structural coupling analysis, dynamic stiffnesses of the deployable antenna aresolved under two operating conditions.