A generalization of the direct-stiffness method of structural analysis

This paper piesents a generalization of the direct-stiffness method of structural analysis which is expected to be of particular value in the analysis of plate and shell bending problems The methods given eliminate the difficulties encountered in obtaining continuity of deflection and slope between neighboring elements in the structure idealized by a finite element representation This is accomplished by formulating the method as a variational problem, thereby gaining for it some of the advantages of a stationary potential energy formulation, and by introducing Lagrange multiplier functions after the manner of E Reissner and K Washizu The plane stress and Kirchhoff plate bending problems are considered