A method for the configurational optimisation of structures

Abstract The problem of designing a minimum weight structure of variable geometry is formulated by the use of optimality criteria to express the member sizes in terms of the configurational variables satisfying the imposed constraints, hence enabling the merit function (weight) to become a nonlinear function of these variables alone. The entire problem can then be solved iteratively with the aid of an unconstrained minimisation algorithm. An approximate method of solution is also presented based on the assumption that there is no redistribution of internal forces while the member sizes are changed to satisfy the optimality criteria. The number of complete structural analyses needed for the evaluation of the objective function is thus considerably reduced, and the problem can be solved more efficiently.