Integration of CAD, FEM and optimization in practice

Abstract

One important parameter in building projects is the cost. Modifications to the dimensions of structures can give changes in the total cost. In such a case, optimisation can be an important tool. The aim of this master thesis is to integrate 3-D CAD and FEM with an optimisation loop to solve structural optimisation problems. The method of developing this goal is to start with small model problems and continue step by step with problems of increasing complexity. The intension is to show that it is possible to find the optimum dimensions for the tender design of a common bridge. Several practical problems are presented in this thesis; simply supported beam, 10-bar truss, reinforced concrete slab, 2D bridge and 3D bridge. CAD, FEM and optimisation programs have been successfully integrated into an optimisation loop. The optimisation loop has been used to find optimum steel to concrete ratios for a reinforced concrete slab for various steel and concrete prices. Results of the 2D bridge problem indicate that a cost saving of approximately 10% can be obtained when a structural optimisation loop is introduced. The results presented in this thesis show that structural optimisation is a practical tool, but further development is needed.