Research On The Stability Of The Sheet Space Structure Based On The Contact Interactive Problems

The stability analysis of space structures is very important problems in structure designing. However,scientificly and conveniently determinating critical load of space structure including sheet space structure is unsolved nicely yet in designing. Comprehensive and objective methods used to stability analysis in structure designing and application are necessarily to be studied.In the sheet space structure system,sheets and metal skeleton interact by transmitting mutual contact force in their uncoordinated joint .The previous researches concerning the interactive problem in the sheet space structure system,are mostly confined to general static analysis.Moreover the interaction of sheet and metal skeleton is often simplified to completed coordination of displacement in common joints.However the theory and trial researches show that the interaction of sheet and metal skeleton has great effect to the stability of the sheet space structure.But contact problem has always been a complex problem in theoretical researches and engineering designs.The constraint equations for a contact state are taken as the essential nonlinear behavior which usually controls the entire process of the deformation.In this thesis, some of the concepts and principles of the stability are induced and elaborated, including mechanism, characteristic, classification, comparison of strength and stability; constraint equation of mechanical state for contact problem is described in detail, the traditional contact model is improved according to nonlinear stability analysis including large deformation and large slippage in the contact part.The finite element method about structure stability analysis considering contact interactive problem is realized aim at the sheet space structure system. The effect of some key points–number of contact elements, contact stiffness, coefficient of friction, contact gap et al, on the solution result of the structure stability analysis is investigated, some useful results are obtained eventually.On the basis of above researches, aiming at three trial models about the sheet space structure system, with the computational models considering contact interactive problem ,the stability of the sheet space structure are analyzed. The computational results are compared with the experimental data. And it is shown that finite model put forward in this thesis can reflect the real stability state of the sheet space structure system, and satisfy the requirement of the engineering computation.It is believed that the methods proposed in this dissertation will be useful to improve the structure of sheet space system, and provide a feasible method for the design of sheet space structure system.