CALCULATION OF THE BUCKLING LOAD AND EIGENFREQUENCIES FOR PLANAR TRUSS STRUCTURES WITH MULTI-SYMMETRY

Abstract In this paper, an efficient method is presented for calculating the buckling load and eigen frequencies of the planar truss structures having double symmetry axes. In this method, considering the axes of symmetry, the region in which structural system is situated is divided into four subregions, namely upper, lower, left and right subregions. The stiffness matrix of the entire system is then formed, and using the existing direct symmetry and reverse symmetry, the relationships between the entries of the matrix are established. Examples are included to illustrate the process of the presented method.