Application of a Non-gradient-based Reliability Method in the Analysis of X-bracing Position in Triangular Steel Structures

In structural engineering, uncertainty can emerge in loading, material and geometry. Structural reliability analysis is a powerful tool for evaluation of the performance of structures under the effects of uncertainty. However, in many real structures, uncertainty is ignored to save computational cost. This ignoring can hide some aspects in the structural performance. In this paper, a recent non-gradient-based reliability method, called Moving Limited Region method (MLR), is to be applied to study the effect of X-bracing position in the steel structures with a triangular plan. The study is carried out for different models, each of which has a different bracing position. Stress ratio is considered to specify the limit state function in the reliability analysis. As a result, the reliability indices of the investigated models, indicating their safety margins, are extracted and the models with the best bracing positions are recognized. Accordingly, it is observed that MLR could be generally recommended, due to its simplicity and applicability, as a potential choice for the reliability analysis of real large-scale structures.