Reliability analysis of RC beams strengthened for torsion with carbon fibre composites

Abstract

Two sets of reliability analyses for two beam series strengthened with carbon fibre composites (CFC) in different ways and subjected to torsional moments are described in this paper. The analyses consider three failure functions and the system is regarded as a series system formed by these three limit state modes. Five random variables are taken into account in the first set of analyses. The analyses are performed for different torsional moment ratios, defined as the ratio of the torsional moment due to live loads to the total torsional moment. The system reliability indexes and the factors of importance associated with each random variable are obtained. In the second set of reliability analyses, only the two most relevant random variables selected in the first set of analyses according to the values of their factors of importance are considered, and new reliability indexes are determined. The examples show that despite the constant value of the total torsional moment, the increase in the torsional moment ratio leads to a decrease in the system reliability levels. The fact that the values of the reliability indexes obtained in both sets of reliability analyses are very similar validates the efficiency of the sensitivity analyses.

Fatigue Reliability Assessment for Orthotropic Steel Decks: Considering Multicrack Coupling Effects

“…(a) (b) Figures [13][14][15][16][17] show the fatigue reliability of steel bridge deck decreases with the increase in annual traffic volume, whether it is the driving lane or passing lane. Compared with the single-crack model, considering the coupling effect of double cracks, the fatigue reliability of the steel deck will be reduced to a certain extent.…”

“…The proxy model method is essentially a fitting technique that can discover implicit relationships between input and output variables and make predictions [13]. At present, a variety of proxy model methods have been developed, including polynomial response surface [14], radial basis function [15], neural network [16] and Kriging [17]. The Kriging proxy model only considers the relationship between variable values, which can be combined with other reliability calculation methods to further improve the calculation efficiency and accuracy.…”

Torsional capacity investigation of reinforced concrete beams with different configurations of welded and unwelded transverse reinforcement

“…The beneficial effect of using continuous spiral stirrups in reinforced concrete (RC) members has been recognized because the spiral reinforcement can enhance the concrete confinement and ductility of RC elements . Several analytical models and experimental programs have been carried out to investigate the behavior of RC beams under torsion. Recently, the use of continuous rectangular spiral reinforcement is extended in RC beams as shear reinforcement instead of the traditional or spiral stirrups .…”