en Optimal design Optimal design پژوهشي Research <span style="font-size:11.5pt"><span new="" roman="" style="font-family:" times=""><span style="letter-spacing:-.2pt">Metaheuristic algorithms are preferred by the many researchers to reach the reliability based design optimization (RBDO) of truss structures. The cross-sectional area of the elements of a truss is considered as design variables for the size optimization under frequency constraints. The design of dome truss structures are optimized based on reliability by a popular metaheuristic optimization technique named Enhanced Vibrating Particle System (EVPS). Finite element analyses of structures and optimization process are coded in MATLAB. Large-scale dome truss of 600-bar, 1180-bar and 1410-bar are investigated in this paper and are compared with the previous studies. Also, a comparison is made between the reliability indexes of Deterministic Design Optimization (DDO) for large dome trusses and Reliability-Based Design Optimization (RBDO).</span></span></span><br> &nbsp; enhanced vibrating particle system, reliability index, dome truss structures, metaheuristic algorithms, reliability based design optimization, large scale trusses 457 475 http://ijoce.iust.ac.ir/browse.php?a_code=A-10-66-350&slc_lang=en&sid=1 P. Hosseini 180031947532846002702 180031947532846002702 No Faculty of Engineering, Mahallat Institute of Higher Education, Mahallat, Iran A. Kaveh Alikaveh@iust.ac.ir 180031947532846002703 180031947532846002703 Yes School of Civil Engineering, Iran University of Science and Technology, Narmak, Tehran, Iran N. Hatami 180031947532846002704 180031947532846002704 No Department of Civil Engineering, Faculty of Engineering, University of Qom, Qom, Iran S. R. Hoseini Vaez 180031947532846002705 180031947532846002705 No Department of Civil Engineering, Faculty of Engineering, University of Qom, Qom, Iran