Document Type : Research Article
School of Civil Engineering, Iran University of Science and Technology, Tehran, Iran
Department of Civil Engineering, University of Sistan and Baluchestan, Zahedan, Iran
In recent years, a number of space structures have been destroyed or collapsed completely due to snow load, external wind load, sudden earthquake impacts and improper traditional design. Not considering uncertainties in materials and external loads can be the main reason in this regard. Therefore, effort has been made in the present study to examine the effects of reliability and sensitivity among random variables and performance functions on the failure probability of single-layer space domes. In order to determine the appropriate and efficient method for reliability analysis in space domes, the reliability analysis was carried out according to approximation (FORM, SORM) and simulation (Importance Sampling, Monte Carlo) methods. The modulus of elasticity, yield stress, external loads, node coordinates, and cross-section of members were considered as random variables to be used in two limit state functions (displacement and ultimate stress). Results of the FORM, SORM, MCS, and IS methods show that in space structures with many random variables, FORM yields good solutions, and sensitivity analyses of the random variables show that the results depend on the type of the limit state functions; a change in the limit state functions will also change the sensitivity. For instance, the values of the sensitivity of the cross-section random variable for the stress and displacement limit state functions are 61% and 8.6%, respectively.