Journal of Theoretical
and Applied Mechanics

47, 3, pp. 667-684, Warsaw 2009

Modeling of initial geometrical imperfections in stability analysis of thin-walled structures

Katarzyna Rzeszut, Andrzej Garstecki
Imperfections are modeled using actual values measured in situ. The method proposed in the paper is based on the concept of developing the imperfections in series of eigenmodes, using a limited number of most critical eigenmodes. Error minimization of this representation is performed. The method is applied to the nonlinear stability analysis of structures made of steel thin-walled cold-formed sigma profiles. FEM with shell elements and the Riks method are used. Numerical examples illustrate the influence of initial imperfections on post buckling behavior of structures.
Keywords: stability analysis; initial geometric imperfections; thin-walled beams; stability of cold-formed bars