Reliability and Sensitivity Analysis of Single-Layer Space Domes

Document Type : Research Article


1 School of Civil Engineering, Iran University of Science and Technology, Tehran, Iran

2 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.‎


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