Natural gas elbow pipe inner surface double-crack interference research method and system

The invention discloses a natural gas elbow pipe inner surface double-crack interference research method and system, and the method comprises the steps: obtaining the data of an outer misalignment welding seam elbow pipe, and building an elbow pipe model; analyzing a double-crack model in which main cracks and auxiliary cracks exist at the elbow and the weld joint at the same time, and comparing a main crack stress intensity factor result subjected to interference with a stress intensity factor of a single-crack model to obtain the influence of the mutual interference effect between the cracks on the stress intensity factor; by changing the position and the type of the auxiliary crack, the change condition of the interference phenomenon between the double cracks influenced by various factors is obtained. According to the method, the real change condition of the interaction influence of the double cracks on the inner surface of the natural gas bent pipe with the misalignment welding seam defect can be clearly