Assessment of the effects of wind loading due to climate change on the reliability of steel pitched-roof portal frames

• Reliability assessment combining loading and resistance. • Implementation of Importance Sampling methodology for structural systems with multiple load combinations. and non-closed form objective functions. • Accurate Importance Sampling methodology with a low computational cost (by a factor of about 1000) when compared to CMC simulations. • Quantitative calculation of the influence of climate change on the reliability of steel pitched-roof portal frames. This paper investigates the reliability of steel structures considering the effects of climate change on wind loading. This assessment is based on 3 climate-change scenarios for the reference wind speed for a specific region in Portugal. The reliability analysis for typical steel pitched-roof portal frames is carried out using the Monte Carlo method, considering simultaneously loading and resistance as random. A design point search method, coupled with an Importance Sampling formulation for multiple load combinations is proposed and implemented, and compared with crude Monte Carlo simulation. It is shown that the proposed method can provide accurate results at a fraction of the number of simulations that are required using the crude Monte Carlo simulation. Finally, the increased probability of failure for the load combinations where the wind is the leading action is quantified for the assumed climate change scenarios.