An approach for the global reliability based optimization of the size and shape of truss structures

¹ Center for Optimization and Reliability in Engineering (CORE), Department of Civil Engineering, Federal University of Santa Catarina, 88040-970 Florianópolis, Brazil
² Center for Optimization and Reliability in Engineering (CORE), Department of Scientific Computing, Federal University of Paraíba, 88040-970 João Pessoa, Brazil
³ Départment Mécanique, Institut National des Sciences Appliquées de Rouen, 76800 Saint-Étienne-du-Rouvray, France

^a Corresponding author: rafael.holdorf@ufsc.br

Received: 3 September 2014
Accepted: 22 April 2015

Abstract

This paper presents a methodology to perform global reliability based design optimization (RBDO) of the size and shape of truss structures. This methodology is comprised by the use of a global constraint and the response surface method to deal with the reliability analysis together with the firefly algorithm (FA) to carry out the structural optimization. The former is responsible for the reduction of the computational cost required in the evaluation of the probabilistic constraints. The latter overcomes the issues related to the non-convexity and mixed-variables of the optimization problem. Two examples are analysed in order to show the effectiveness of the methodology. In these examples, the FA is compared to other two well-known algorithms, the harmony search (HS) and genetic algorithm (GA). As a result, the FA reached the best performance in the examples analysed. All the optima found were checked using a classical first order reliability method (FORM) approach, validating the results provided by the response surface method.