The extended finite element method of multiple crack growth is presented. The crack junction is analyzed using the junction enrichment function; the generalized nodal shape functions are used in a cluster of nodes around the cracks

a ramp function is used to avoid the blending element problem. These techniques can effectively improve the accuracy of stresses in the vicinity of crack. The mortar method (segment-to-segment contact approach) in combination with the augmented Larange method is adopted to establish the contact conditions between crack faces. Thus the contact is modeled precisely; and it is convenient to solve the control equations. Several numerical examples are analyzed as follows: (1) computing the stress intensity factors of the cross crack

the proposed method can obtain higher accuracy; (2) simulating the growth and coalescence of multiple cracks

the numerical results are good in agreement with the experiments; it shows the reliability of the present method.