Sensitivity analysis of double layer Diamatic dome space structure collapse behavior

Abstract

Collapse behavior of double layer dome space structures depends on different factors such as load pattern, material mechanical properties, and member’s physical characteristics, which have a random nature that makes it difficult to predict accurate behavior of this type of structure. In this paper, in order to comprehensively assess the double-layer dome space structure behavior, different uncertain parameters such as the mechanical characteristics of steel material, mass and applied gravity load, and also structure’s and members’ geometric imperfection are taken into account in nonlinear static pushover analysis. Different models with rise to span (R/S) ratios of 0.1, 0.2, and 0.3 under incremental symmetric and asymmetric snow loads are investigated. In order to determine the importance of these uncertain parameters and rank them according to their effects on the structural response parameters, two different methods of Tornado Diagram Analysis (TDA) and First-Order-Second-Moment (FOSM) are utilized. Using these methods enables the sensitivity analysis of the collapse behavior of the structures to the considered random variables. The results of the analyses reveal that there is a close agreement between the TDA and FOSM analyses results in ranking the random variables according to their importance. In addition, these methods highlight the high sensitivity of the structural response parameters to the various sources of uncertainty, and indicate the necessity of applying these uncertainties in the analysis and design of this type of structure.