Research Of Structural Parameters On Buckling And Postbuckling For Thin-walled Beams Under Bending And Shearing Load

Aluminum reinforced thin-walled beams are the major load-bearing members of the aircraft structures, whose static failure is commonly caused by structural buckling phenomena. The thin-walled beams can continue to bear load when their structure have lost the stability. Buckling problems of thin-walled beams involve too complex interaction between geometric nonlinearity and elastoplasticity to be analytically solved; it further complicates the buckling issue that flexible structural design always induces comprehensive local-global interaction; moreover, there are many factors affecting buckling behavior of thin-walled beams, which mean multiple challenges for accurate numeric simulation. Therefore, buckling behavior of thin-walled beams is always an important consideration in the field of structural engineering. Taking into account practical engineering technical requirements, this paper combines analytical solution, finite element method and experimental approach to investigate resistance of high-strength aluminum thin-walled stiffened beams under combined action of bending and shear forces, with the aims of exploring resistance mec hanism of thinwalled beam and proposing design guidance. The primary work and achievements of the Master thesis are as follows:Taking a beam of the metal wing under bending and shearing load test as the background, first, the linear buckling analysis of the thin-walled beams have taken. Seting up finite element model of the thin-walled beams, we have got the critical buckling load, buckling modes and stress or strain distribution when buckling occurs by Eigenvalue analysis. And these datas can be provided for the non-linear buckling analysis.Secondly, nonlinear analysis conducted after buckling of the thin-walled beams based on material nonlinear and geometric nonlinear. And considering that the factors of affecting the stability of thin-walled beams in projects are so many, flange thickness ratio, stiffener distribution, hole position, hole size, hole shape, etc also have considered in this paper, providing a reference for engineering practice in the design of thin-walled beams.