When designing thin-walled structures, the results of theoretical studies of structural mechanics and the theory of elasticity are used. However, the disunity of methodological information makes it difficult for them to be used directly by the designer. In addition, most of the existing constraints allow you to determine only the bearing capacity of the structure, which does not fully satisfy the design engineer, whose main task is to determine the parameters of the optimal structure at a given load. In the proposed book, an attempt is made to revise and systematize the known methodological material and, on this basis, develop methods for determining the optimal design parameters.