For h1 ¼ 0, Figs. 17 and 18 show the normalized SIFs, EDIFs and ERRs for the crack tip A and B, respectively. It is validated
again that the added layer has an important influence on the normalized EDIFs for the two crack tip. The variations of the
normalized SIFs and EDIFs for the crack tip A are opposite to those of crack tip B. These aforementioned properties are useful
for engineering designs, as an appropriate angle and thickness of M2 may decrease the values of fracture parameters.