Abstract
A simple and computationally inexpensive approach is presented for obtaining the maximum load factor of an elastic structure considering reduction of load-carrying capacity due to inevitable initial imperfections. The structure has a stable bifurcation point if no initial imperfection exists. An anti-optimization problem is formulated for minimizing the maximum loads reduced by the most sensitive imperfection within the convex bounds on the imperfections of nodal locations and nodal loads. It is shown in the examples that a minor imperfection that is usually dismissed is very important in evaluating the maximum load of a flexible structure.