The finite element method is presented for determining initial shear buckling stresses and buckling modes of any shear wall consisting of a stiffened flat steel plate. The shear wall is idealized by triangular flat plate elements and beam elements. Especially, the constant strain triangular element with only six degrees of freedom is used for the lateral bending stiffness matrix and for the initial stress matrix. Such elements were originally proposed by Morley. Jenning's method was employed for the eigen-value analysis, and some corrections were made in that method so as to introduce Cholesky Factorization which is very effective for the large system stiffness matrix. Four types of shear wall stiffened with rib were analyzed and the values obtained were compared with those of energy method and experimental ones. The initial shear buckling stresses by this method proved slightly low compared with the energy ones, and the buckling modes showed favorable coincidence with the experimental results. Consequently, this method is very useful in buckling analysis of shear wall stiffened with rib.
