Optimal layout of trusses considering expected consequences of failure

Thaís Gomes Pedrosa¹; André Teófilo Beck¹

¹ Universidade de São Paulo

doi:10.20906/CPS/CILAMCE2017-0087

Resumo

Failure of engineering structures is, to a large extent, controlled by material ductility. However, for truss-like structures, topology also has a strong impact on failure modes, load redistribution and eventual progressive collapse. This paper addresses optimal layout of truss-like structures, considering the effects of uncertainties and expected consequences of failure. By quantifying consequences of primary failures, of progressive and final collapse, and of direct/indirect failure costs, different optimal topologies are achieved. The study considers non-linear geometrical and material behaviors, which leads to highly non-linear objective functions. Optimization for minimal total expected life-cycle costs, including the expected costs of failure, also leads to multi-modal objective functions, requiring non-trivial solutions by global optimization algorithms. The study addresses optimal design of structures such as steel-frame towers, antennas, domes and shells.

Palavras-chave: Risk Optimization; Ground structure approach; non-convex objective functions; Progressive Collapse