Digital Repository, FCP2003

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Crack Path Simulation by the MVCCI Method and Experimental Verification for Curved Fatigue Cracksin the Neighbourhood of a Circular Hole
H. Theilig, M. Wünsche, R. Bergmann

Last modified: 2013-12-02

Abstract


The Modified Virtual Crack Closure Integral (MVCCI) method has beenproved to be a highly effective numerical procedure for the analysis of various crackproblems in linear elasticity. In the present paper it will be shown that the MVCCImethod in conjunction with multiple mesh analysis can also readily be utilised for thenumerical prediction of curved fatigue crack growth under proportional loading condi-tions. Further it will be shown that the common computer-aided two-dimensional crackpath prediction can be considerably improved in accuracy by using a predictor-correctorprocedure. In combination with the MVCCI method, this results in a step-by-step para-bolic approximation of the simulated crack path. By this method both the new locus of thecrack tip and the slope of the crack path at this point can be computed simultaneously bythe SIFs by only one virtual tangential crack extension with respect to the previous step.In order to evaluate the validity and efficiency of the proposed higher order crack pathsimulation method in relation to the well-established basic strategies, experiments ofcurved fatigue crack growth in the neighbourhood of a circular hole are carried out withtwo specially designed specimens under proportional lateral force bending. In all casesconsidered, the computationally predicted crack trajectories show an excellent agree-ment with the different types of curved cracks that are obtained in the experiments as afunction of the position of crack initiation.

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