Yuriev A.G., Zinkova V.A., Smolyago N.A., Yakovlev O.A. STRUCTURE OPTIMIZATION OF THE METAL TRUSSES Efficient method structure determination of metal truss has variational basis. Variational statement of problem is a fundamental approach of intention realization. From it follows universal criterion of optimization, connecting with minimum of potential energy of the system in function space expanded at the expense of function fields of configuration and (or) material moduls. Under the condition of homogeneous linear elastic material optimal truss represents as uniresistant virtual system with internal forces N/ i ( i decrease coefficient of designed resistance of material). As numerical example was considered the determination of optimal structure of the truss with the consoles. Of the four variants, the minimum amount of material obtained for the truss with downward diagonals and the horizontal fragment of the upper belt. At the stage of optimal geometry determination of a truss at a given geometry the problem is solved strictly by variational methods of structural synthesis, and at stage of the topology optimization by comparison of admissible variants. However, in both cases is present a single criterion of optimality, carrying into minimum of material expense.