PSI - Issue 2_A

Sascha Hell et al. / Procedia Structural Integrity 2 (2016) 2471–2478 S. Hell and W. Becker / Structural Integrity Procedia 00 (2016) 000–000

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Of course, the authors are aware that the considered examples might be considered to be of rather academic nature. For example, deformation mode co2 alone would probably not lead to a crack extension starting from the crack interaction point as the associated point singularity is actually weaker than the line singularities along the crack fronts. The consideration of a hypersingularity (deformation mode co1) with a theoretically infinite di ff erential energy release rate (but finite incremental energy release rate) might also be questioned. Nevertheless, the obtained results were checked regarding their convergence and found to be accurate within about 0.1% from the extrapolated values. Incidentally, the enriched formulation of the SBFEM was shown to be clearly superior to the standard formulation regarding convergence and accuracy. Moreover, the presented calculations can be seen as a first step towards the application of the enr SBFEM to the concept of Matched Asymptotics, which seems especially promising facing the overwhelming variety of generally admissible crack extensions in 3D fracture mechanics problems within the framework of FFM (Leguillon, 2002; Hell et al., 2014; Leguillon, 2014). Indeed, the authors expect the enr SBFEM to be especially suited for this purpose as infinite domains can quite simply be realised using this method. Finally, in ongoing works, the enr SBFEM has been extended to the anisotropic case of a crack impinging on an interface which clears the way for the application of the method to the practically relevant situation of two meeting inter-fiber cracks in a composite laminate. Acknowledgements The authors appreciate the financial support of the German Research Foundation DFG, project BE1090 / 35-2. Anderson, T. L., Anderson, T., 2005. 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