On The Quantitative Analysis Finite Element Modeling Of Contact Problems For The Sheet Space Structure

Sheet space structure system is a new space structure system composed of light-quality,high-strength sheet and thin wall metal skeleton in a special way..By applying the aviation construction principle to the civil engineering,bringing direct stress into very thin sheet,sheet space structural system can make use of the construction materials economically and bear reasonably.But in actual construction analysis,how to model this structure system computationally depends on the research of the interactive problems of sheet and metal skeleton.In the sheet space structure system,sheets and metal skeleton interact by transmitting mutual contact force in their uncoordinated joint.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.The previous researches concerning the interactive problem in the sheet space structure system,are mostly grounded in qualitative analysis.Quantitative analysis is done rarely, which concentrates on the problem of how to establish a reasonable finite element analysis model, and more importantly, how to set contact elements between sheet and metal skeleton.Therefore,making a quantitative analysis of the contact interacting problems in this construction system will make some valuable contribution to the design and application of this structure system.In this thesis,constraint equation of mechanical state for contact problem is described in detail.The whole solution process of inducting it to function in virtue of constraint variational theory is described and analyzed,and then proposes the formula based on the finite element method.Aiming at sheet space structure system,the finite element method in quantitative analysis about contact problem is studied in this thesis.In order to find out how different quantities of the set contact elements influence the mechanical capabilities of components in the sheet space structure system,the different mechanics indexes of sheet space structure system according to different contact element setting quantities in each load case are analyzed.And it obtains some very useful results eventually.Computational model about contact put forward in this thesis can reflect the real working state of sheet and metal skeleton in Sheet space structure system,and satisfy the requirement of the engineering computation.It is hoped that the findings of this thesis can be useful to improve the structure of sheet space structure system ,and provide a feasible method for the design of sheet space structure system.