Analysis Of The Thin-walled Spatial Steel Structure With Finite Element Method And Program Simulation

As the light steel structures are extensive application in engineering, the problem which the application of thin-walled elements become more and more outstanding and the force analysis become extremely important. The biggest difference between the thin-walled member and the entity component is that the buckling deformation of the cross-section can't be neglected as the relatively secondary factor. The spatial response and deformation of the thin-walled structures which are made up of thin-walled member are all prominent extremely, whether they're from thin-walled beam itself or the thin-walled construction, so we must carry on the earnest analyses to them.Thought the main characteristic of the open thin-walled frame structures, in this article we calculate the geometric parameter with many kinds of thin-walled member of open cross section according to Vlasov's thin-walled theoretical, which can made up the deficiency of section's correlation parameters in "Specification for the Design of Thin-wall Steel Structures (GB50018-2002)".We analyze on the static to the space thin-walled elements under the constraint distorsion state and derive the formula of torque and bimoment of member's vertex under the concentrated torque and the uniformly distributed torque. When research of the element stiffness matrix, we discuss the difference of the 14×14 order matrixes including the influence of warping by the matrix displacement method and the finite-element method. It gains the tallied application range of two kinds of matrices; we analyze the structure by the initial parameter method and the finite-element method for an example and compare to the advantages and disadvantages and influence of warping to stress.On the basis of static analysis, we analyze the geometric nonlinearity of the structures according to iterative method with moving-coordinate and calculate the yield load. When we analyze the vibration characteristic, we adopt the lumped mass matrix and determinant search method to calculate the natural frequencies and mode vectors to offer theoretical basis for structures seismic design.We compile the program that can use in the thin-walled structure considered the warping effect in the Fortran 90. We simulate and analyze the light steel structure through the example of 14 floors and calculate the yield load and the natural frequencies. Compare the result that considered the warp influence to that not be, it show the clear influence of the warping to the internal force and the stress.