Analysis of multiple crack growth using extended finite element method

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.