convergence of finite element approach; bending of plates with ribs; density theorem
In the present paper the convergence of the finite element method to the solution of the problem of a plate with ribs which are stiff against torsion in the sense of Vlasov is studied. According to the conclusions of a paper by the author and J. Haslinger it suffices to prove a density theorem (Theorem 2.1).
 P. G. Ciarlet P. A. Raviart: General Lagrange and Hermite Interpolation in $R_n$ with Aplications to Finite Element Methods
. Arch. Rat. Mech. Anal., sv. 46, 1972. MR 0336957
 J. Haslinger P. Procházka: Conforming finite element method in the problem of a plate with ribs
. Apl. mat. c. 4, sv. 22 1977. MR 0449141
 V. Janovský P. Procházka: The nonconforming finite element method in the problem of clamped plate with ribs
. Apl. mat. č. 4, sv. 21, 1976. MR 0413548
 V. Janovský P. Procházka: Convergence analysis of a nonconforming finite element method solving a plate with ribs
. Apl. mat. c. 1, sv. 23, 1978. MR 0462100
 J. Nečas: Les méthodes directes en théorie des équations elliptiques
. Academia, Praha, 1967. MR 0227584
 P. Procházka: Plate with ribs. (in Czech). CSc-dissertation, ČVUT, Praha, 1975.