Reliability assessment of reinforced concrete structures based on random damage model

A stochastic model is developed to describe the fracture behaviour of concrete fibres at micro-level, and a probabilistic relation between the fibre strain and the concrete damage variable is established. In this context, the concrete damage evolution can be quantified by two representative random variables. In this regard, the number of random variables employed in potential reliability assessment studies can be greatly reduced. The accuracy of the proposed method is verified by comparing the first- and second-order moments of the stochastic damage evolution with the corresponding closed form solutions. Further, the proposed method is applied to the non-linear analysis and reliability assessment of a five-story reinforced concrete frame, and the results show that it is quite efficient for stochastic response determination and reliability evaluation of complex structures.