QR-Method For Nonlinear Stability Analysis Of Tall Frames Structures With Initial Geometrical Imperfection

There are lots of structure frames in high building and beams and columns are main load-bearing structure. If it is steel structure frames, it has some advantages including high strength, large extension,good anti-seismic capability,rapid construction speed and so on. Especially nowadays, structures trend to light-thin modelbecause of the development of design theory and material property. It is a highlight that steel structures total stability is calculated.In this thesis, the problem of nonlinear static stability analysis of structure frames in high buildings with initial geometrical imperfection . The author exact tangent stiffness for imperfect beam-column members and establish the functions of stability on the basis of QR-method ,according to the theory of geometrical nonlinear and the theory of stability, educe the stability equation of structure based on variational principle . The big distortion geometrical nonlinear was considered by the stability equation,the author simplified the problem of geometrical nonlinear through ignored quadratic term and reserve...