Reliability of Single-Layer Steel Space Domes under the Effects of the Changes in the Height-to-Span Ratio

In space domes, geometrical changes are the main factors that determine the forces in the structural members. This paper has addressed the effects of the height-to-span ratio variations on the reliability of space domes. Applied loads, nodes coordinates, member’s cross-section, modulus of elasticity, and yield stress are the random variables, and FORM (first-order reliability method), SORM (second-order reliability method), MCS (Monte Carlo sampling) and IS (importance sampling) were the methods used to evaluate the reliability of such structures. Results showed that FORM yielded better solutions; reliability increased with an increase in the height-to-span ratio, and a change in the performance function changed the reliability index and sensitivity coefficient. Hence, for domes with height-to-span ratios less than 0.3, the displacement performance function is the effective function and for ratios greater than 0.3, the stress performance function should be considered as the critical function.