According to the principle of minimum potential energy, finite difference schemes for small deflection bending of thin elastic plates with edge beams are obtained with FDM based on the principle of variation.The schemes depend only on mesh points in plates .They avoid problems with fictitious mesh points.Difference equations are programed with MATLAB and numerical simulations are shown.

Starting from the principle of minimum potential energy, a difference scheme is constituted for solving the bending problem of plates with their edges threngthened by beams,numerical results are presented, and the law of interaction between the plates and the boundary beams is investigated qantitatively.

Starting from the principle of the minimum potential energy, the governing differential equation and the boundary constraint conditions for the bending problem are differenced unitedly and the difference schemes which depend only on the mesh points in plate area are obtained. A method to solve the difference equations by means of combining the direct manner with Gauss-Seidel iteration method is proposed. And a numerical example is given in the paper.