This article investigates the fatigue performance of composite dowels under combined shear and tension loads, which has not been previously considered. Experimental and theoretical studies were conducted, including a fracture mechanics‐based theory validated by a specialized fatigue experiment. The effect of steel teeth plate thickness and tension on fatigue behavior was examined through parametric numerical analysis, and fatigue detail classifications for joints are proposed based on EN 1993‐1‐9 and International Institute Welding provisions (s. paper Xiong, Z. et al., pp. 52–62).