Exact Constantes of Energy Equivalence in the Method of Recalculation Boundary Conditiones for Biharmonic Equation

The iterative algorithm with economical preconditioner for numerical solution of elastic problem in approximation of plate theory with mixed boundary condition proposed and grounded. Exact constantes of energy equivalence for optimization of iteration method are obtained. Inversion of preconditioner is equivalent to double inversion of discrete analog of Laplace operator with Dirichlet boundary condition.