engleski

Validation of crack arrest technique by numerical modelling

Parameters affecting efficiency of crack arrest technique, based on cold working of the crack arrest holes (mandrelizing and inserting of pins) are investigated, with respect to their influence on fatigue life (i. e. life to initiation of a new crack, after the previous one was repaired). To allow practical application of obtained results, specimens describing behaviour of a real structural part with a crack are selected. Specimens made of AlCuMg2 and steel pins are analysed. Non-linear calculation of strains and stresses in specimens is based on finite element analysis, considering elastoplastic material behaviour and taking kinematic non-linearities into account. Numerical estimation of fatigue life is based upon Manson-Coffin equation and modified Smith-Watson-Topper's parameter. Numerical results are compared with experimental results from the literature and a very good agreement is found. Recommendation for selection of parameters of crack arrest holes procedure, valid for analysed cases, is given in a simple tabular form.

crack arrest holes; crack initiation; fatigue life; finite element analysis

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