UPPER AND LOWER BOUNDS FOR THE COLLAPSE LOAD FACTOR OF RECTANGULAR GRIDS USING FEM

Despite widespread application of grillage structures in many engineering fields such as civil, architecture, mechanics, their analysis and design make them more complex than other type of skeletal structures. This intricacy becomes more laborious when the corresponding analysis and design are based on plastic concepts. In this paper, Finite Element Method is utilized to find the lower and the upper bounds solutions of rectangular planner grids and this method is compared with analogues Finite Difference Method to indicate the efficiency of proposed approach.