Design of truss-structures for minimum weight using genetic algorithms

Optimization of truss-structures for finding optimal cross-sectional size, topology, and configuration of 2-D and 3-D trusses to achieve minimum weigh t is carried out using real-coded genetic algorithms (GAs). All the above t hree optimization techniques have been made possible by using a novel repre sentation scheme. Although the proposed GA uses a fixed-length vector of de sign variables representing member areas and change in nodal coordinates, a simple member exclusion principle is introduced to obtain differing topolo gies. Moreover, practical considerations, such as inclusion of important no des in the optimized structure is taken care of by using a concept of basic and non-basic nodes. Stress, deflection, and kinematic stability considera tions are also handled using constraints. In a number of 2-D and 3-D trusse s, the proposed technique finds intuitively optimal or near-optimal trusses , which are also found to have smaller weight than those that are reported in the literature. (C) 2001 Elsevier Science B.V. All rights reserved.