Development of a new method for estimating the fatigue life of notched specimens based on stress field intensity

•Improved the estimation accuracy of the Yao’s stress field intensity method.•This method considered that each point in the fatigue failure region had an “obstructive effect” on fatigue damage at the peak point.•Propose a new definition of fatigue failure region.•Optimized the integral form of the Yao’s stress field intensity method. In this study, the existing problems of the traditional Yao’s stress field intensity method were improved. Based on the effective distance concept of the advanced volume method, an idea to define an “invisible field boundary” in the fatigue failure region was proposed. The new method considered that each point in the fatigue failure region had an “obstructive effect” on fatigue damage at the peak point. A new concept of “Auxiliary part” and its mathematical definition were proposed. Finally, the modified stress field strength method was applied to a notched specimen. It was found that the proposed method yielded more accurate results than the traditional stress field intensity method.