The study includes considerations on the numerical methods of obtaining the correct forms of deformation of thin-walled plates subjected to pure shear, operating under conditions of critical loads. Selected methods were presented and subjected to comparative tests, allowing for the obtaining of a state of large deformations of a perfectly flat system, loaded in its plane. These methods are based on application various forms of initial imperfections into the system, either geometrically or physically. A new solution was proposed in this area, differing in its essence from most commonly used solutions.