System Reliability Based Design Optimization of Truss Structures with Interval Variables

  • Mohammad Zaeimi

    Young Researchers and Elites Club, Science and Research Branch, Islamic Azad University, Tehran, Iran

  • Ali Ghoddosain

    Faculty of Mechanical Engineering, Semnan University, 3513119111 Semnan, Iran


New products ranging from simple components to complex structures should be designed to be optimal and reliable. In this paper, for the first time, a hybrid uncertain model is applied to system reliability based design optimization (RBDO) of trusses. All uncertain variables are described by random distributions but those lack information are defined by variation intervals. For system RBDO of trusses, the first order reliability method, as well as an equivalent model and the branch and bound method, are utilized to determine the system failure probability; and Improved (μ + λ) constrained differential evolution (ICDE) is employed for the optimization process. Reliability assessment of some engineering examples is proposed to verify our results. Moreover, the effect interval variables on the optimum weight of the truss structures are investigated. The results indicate that the optimal weight depends not only on the uncertainty level but also on the equivalent standard deviation; and a falling-rising behavior is observed.

Keywords: reliability based design optimization, interval variables, improved (μ λ) constrained differential evolution (ICDE), structural optimization
Published online
How to Cite
Zaeimi, M., Ghoddosain, A. “System Reliability Based Design Optimization of Truss Structures with Interval Variables”, Periodica Polytechnica Civil Engineering, 64(1), pp. 42-59, 2020.
Research Article