Dynamic programming and direct interaction for the optimum design of space structures

Abstract

A computer technique is proposed for a simple practical method of automatically designing skeletal structures. Dynamic programming is used to find the optimum geometric configuration of the structural members, while the member sizes are proportioned by direct iteration. The computational effort required to find the best possible design for large structures can become unmanageable without the use of Dynamic Programming. This technique simplifies this problem by a process of intermediate decisions which are made at each stage of the solution. Dynamic Programming is applied to tower structures which can be regarded as discrete substructures. The configuration of each substructure is defined at its upper and lower interfaces by a set of state variables. An optimum weight design can be found by selecting the best configuration and hence the best state variables at each interface. Each alteration of the geometric configuration of a substructure effects its weight. Consequently, a series of decisions based on accumulated weight must be made so that the chosen configuration at each interface produces the optimum weight design for the entire structure.