Numerical solution of the problem of a plate with ribs by the finite element method is studied in this paper. Since the regularity of a solution of the trial problem is not a priori known, the convergence of the finite element method is ensured when a space of smooth enough functions which is dense in the trial space is found. To find such a space is the main goal of this paper. Some numerical results are compared with the folded plate method in the last part.
 P. G. Ciarlet P. A. Raviart: General Lagrange and Hermite Interpolation in $R_n$ with Applications to Finite Element Methods
. Arch. Rat. Mech. Anal., sv. 46, 1972. MR 0336957
 J. Haslinger: Sur la solution d'un problème de la plaque
. Aplikace matematiky, č. 5, sv. 19, 1974. MR 0369902
| Zbl 0324.73049
 J. L. Lions E. Magenes: Problemes aux limites non homogenes et applications. DUNOD - Paris - 1968.
 J. Nečas: Les méthodes directes en théorie des équations elliptiques
. Academia, Praha 1967. MR 0227584
 V. S. Vladimirov: Уравнения математической физики
. Наука, Moskva 1967. Zbl 0234.60109
 V. Křístek: Theory of solution of box girders. SNTL Prague, 1974 (in Czech).