Stress intensity factor solution for edge interface crack based on the crack tip stress without the crack

•A new solution for the stress intensity factor of an edge interface crack was proposed.•The factors normalized by the crack tip stress were indicated for whole material range.•The normalized factors of small crack were independent of the geometrical condition.•By analyzing the sandwiched butt joint, the usefulness of the solution was confirmed. In this paper, a new solution is discussed for the stress intensity factor of an edge interface crack. The intensity of the singular stress field (ISSF) at the interface end before appearing the edge interface crack is distinguished from the stress intensity factor (SIF) of the interface crack itself. By considering those two distinct double singular stress fields, the ISSF and the SIF are discussed under arbitrary material combinations. By focusing on the crack tip stress without the interface crack σy(a), the SIF of the edge interface crack can be expressed conveniently. This is because the crack tip stress without the interface crack is reflecting the ISSF at the interface end. The SIFs based on the crack tip stress without the interface crack are indicated by varying the crack length and material combination. It is found that the normalized SIFs (F1,int and F2,int) based on σy(a) are independent of the geometrical condition for the wide range of the crack length.