An evaluation method for uncertainty in failure load of CFRP composite bolted joints

Bolted joints are the weak points of composite structures. Therefore, the considerable uncertainty in mechanical properties of the bolted joints not only prevents advanced composites from efficient applications, but also threatens the safety and reliability of the structures. In order to quantitatively evaluate the uncertainty in failure load of carbon fiber reinforced polymer (CFRP) composite bolted joints, an efficient and accurate analysis method was proposed based on the numerical progressive damage model and interval analysis method. The proposed method was used to predict the uncertain failure load of T800 carbon fiber/X850 epoxy composite bolted joint. The predicted results were compared with the experimental outcome. The small error less than 2% between the predicted and experimental results validates the effectiveness of the proposed method. According to the predicted results, the interval of failure load of the T800 carbon fiber/X850 epoxy composite bolted joint is 19.25 kN, 22.75 kN with the deviations from the design expected values of −9.8%, 6.6%.