Influence of variable orthotropy upon the stability of thin-walled rectangular plates

The author analyse the stability loss in thin-walled orthotropic plates, their principal directions of orthotropy being parallel to the wall edges, for plates with the orthotropy ratio, $\beta=E_x/E_y$ varying widthwise. The analysis was carried out within the elastic range. Numerical tests were made on thin plates with the loaded edges simply supported; unloaded edges were tested for different kinds of support (clamped, simply supported, free-edge). Plates were subject to loads causing uniform and linearly varying displacement of edges. The problem was solved using Koiter's first-order asymptotic theory of conservative systems stability (Koiter, 1963).

Results of numerical calculations were presented as graphs describing the relationship between a critical value (force or moment) and the parameter defining orthotropy across the plate width.