xfem for beginners

vinh phu nguyen — Fri, 05 Sep 2008 19:12:59 -0400

Hi Mike,

In below, I am trying to answer your questions.

1. The asymptotic functions are only used for cases where exact solutions are known such as in linear elastic fracture mechanics (all we know the Westeergaard solution.). In other cases, only enriched by Heaviside function is enough as done in cohesive cracks modelling.

2. You were talking about crack propagation simulation with xfem. So, starting with an existing crack, the nodal unknowns are computed, including the displacement dofs (u) and enrichment dofs (b). Then, you then use some criteria to compute the crack propagation angle, and provided a crack advance length, you update the crack geometry, then the process is repeated again.

There are many criteria for this depending on LEFM or cohesive cracks. Noting that xfem can be used for crack initiation too.

There is a simple xfem Matlab code, available for free for which you can get by writing to Dr. Stephane Bordas at stephane.bordas@gmail.com.

You can also write to me at nvinhphu@gmail.com for discussion concerning xfem, if you like.

Good luck.

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xfem for beginners