Research On Modelling Method For Thin-walled Structure Based On Super-element

With the development of industry technology, the current level of strength analysis for aircraft has reached a new height, it allows us to carry out almost any analysis with a fine precision by FE softwares. However, with the increasing of complexity of the model, the number of the element become more and more, computation time will be increased and the effect of the computation will be reduced. In the early design phase, there has number of possible structure schemes and lots of computational load cases, and much time is spent on the computation. Therefore, it is an immediate problem to decrease the complexity of the model to improve computational efficiency.In this paper, a new modeling method based on super-element is proposed. The method suited for stress-strain analysis of the thin-walled wing or fuselage structure in the early stage of project. In this method, thin-walled structures are divided into seve8 ral super-elements based on some hypothesis in finite element discretion and each super-element contains multiple rod elements and panel elements. By this way, the total number of the element is greatly reduced so the computational efficiency is improved. Computational formula for the super-element stiffness matrix and global stiffness matrix are deduced using virtual displacement principle and the equivalent load from temperature in thermol load case is obtained. A program written by MATLAB is used to carry out stress-strain state by the new method. At last, the method and the program are verified through several examples. It is showed that, by the new method computational efficiency can be improved and computational accuracy can meet the engineering requirements.