Analysis Of The Thin-walled Bar's Restrained Torsion

The thin-walled structure is a very popular structure type. This covers building, bridge, ect. Usually, it is composed of sheet metal, shell, thin-walled. Satisfied the needs of strength, its weight is lighter, strength is greater, the material could be more efficiently used in comparison with the other structure. So the thin-walled structure is widely used in engineering structure. With the enlargement of range, which the thin-walled structure is used in engineering, the thin-walled structure theory and the application technique is continuously developing forward. The research of thin-walled structure behavior has become important research field of elastic mechanics.In this paper the research on thin-walled structure is onetype of particular thin-walled structure —the thin-walled bar structure. The author summarized classic theory and FEM method of this structure.The classic theory may be divided into Vorousov open section and Wumanski closed section thin-walled bar theory. In this paper, the author discussed the theory, summarized the effect of beam geometry feature on the theory, put up the modified formula of maximal normal stress.In the paper, the stress of simply supported beam is calculated when it is loaded with the moment of torsion. The stress results is obtained by VC program, using the finite element software— ANSYS, the structure is analyzed.The classic theory had derived the fundamental differential equation of shell structure. It is difficult to solve the equation directly, so the numerical method was adopted.In this paper, the linear and nonlinear behavior of beam is analyzed. The conclusion can be drew that when the span of beam exceeds 18m, the effect of deformation on the stress should be considered. This conclusion is quite valuable in engineeringstructure design.