DISCRETE-FIELD STABILITY ANALYSIS OF X-BRACED LATTICES

The techniques of discrete-field analysis are used to perform an elastic-stability analysis of a three-dimensional X-braced lattice used as a compression member. Regardless of the humber of joints in the system, the solution for the critical buckling load is reduced to solving for the eigenvalues of a 5 x 5 matrix. The formulation thus derived is used to develop a series of curves showing the critical buckling load for various X-braced-lattice configurations and geometries. A comparison of the critical buckling loads for the X-braced lattice indicates that the modified Euler buckling load may vary up to 30% from the loads obtained by the discrete-field-analysis method. The study also shows that as the number of panels increases from four to 32, the buckling-load ratios also increased. The X-braced-lattice depth will affect the buckling load of the lattice system. Variations in chord-member areas create variations in buckling-load ratios. The effects on the buckling ratios of the last two factors tends to diminish as the number of panels increases.