[1]Department of Civil Engineering University of Sistan and Baluchestan Zahedan 9816745565 Iran;
[2]Department of Civil Engineering The University of Memphis Memphis TN 38152 USA;
[3]Department of Civil Engineering Velayat University Iranshahr 9911131311 Iran;
reliability-based design optimization; trusses; sensitivity analysis; shifting technique; cubic B-splines; response surface method;