DETERMINING LOAD AND RESISTANCE FACTORS BASED ON THE EXPONENTIAL THIRD-MOMENT RELIABILITY INDEX

Load and resistance factors design is widely used in structural codes for reliability-based limit state design. Among various design methods, third-moment methods are widely used because they do not require double iterations based on the derivative and the probability distribution of random variables. However, the accuracy of the existing third-moment methods restricts the skewness to a narrow range, which does not satisfy the structural design under the large range of the skewness. This paper proposes a simple and accurate method for determining the target mean resistance and load and resistance factors based on the newly proposed exponential reliability index, which eliminates complex iterations and expands the applicability of existing third-moment methods. Several examples are provided to demonstrate the applicability and accuracy of the proposed method for determining load and resistance factors.