Beam Element Analytical Model of Thin-walled Beam Structure
MB Guo-jun , QIAN Ruo-jun (Tongji University, Shanghai 200092, China)
In this paper, a kind of thin-walled beam element analytical model that can be used in the elastic analysis of thin-walled beam structure was presented. Based on the space beam element analytical model, an improved displacement model was adopted. It can consider the possible patterns of the deformation of thin-walled beam, such as tension or compression, shear, bending, torsion and warping, and their coupling effect. Thus the element shape function was derived. According to the definition of Green strain, the expression of normal strain of element was constituted using the method of expanding Taylor series. And the corresponding thin-walled element stiffness equation was formulated. The apparent formulation of element stiffness matrix under the local coordination was attained. According to the thin-walled beam element analytical model obtained by this paper, the interrelated structural calculating program was worked out. The numerical example validates the element stiffness matrix. Finally the comparison between the space beam model and the thin-walled beam model indicates the effect of section warping on the thin-walled beam structure.