Abstract

CONRADIE, J.H.; BECKER, T.H.  and  TURNER, D.Z.. Peridynamic Approach to Predict Ductile and Mixed-Mode Failure. R&D j. (Matieland, Online) [online]. 2019, vol.35, pp.1-8. ISSN 2309-8988.  http://dx.doi.org/10.17159/2309-8988/2019/v35a1.

The peridynamic theory has been developed to address problems in solid mechanics regarding fracture through its integral non-local basis. It has been successful in predicting brittle cracking, however, uncertainty still remains with regards to mixed mode and ductile fracture. This work presents a study in using peridynamics to simulate fracture in mixed mode or ductile type fractures. The results are presented as a quantitative comparison between experimental tests and numerical simulations. Standard compact tension tests were performed on polymethyl methacrylate (PMMA), stainless steel 304L and aluminium 1200H4 to obtain the respective JR-curves and critical energy release rates, J_ic. In addition, digital image correlation was employed to allow for qualitative observation of the fracture process and choice in peridynamic input parameters. An equivalent critical stretch was determined for each material and applied to an Arcan geometry. It is shown that the energy release rate for mode I and mode II should be considered separately. Mixed mode type failures cannot be simulated accurately by a single critical stretch criterion. Furthermore, ductile fracture requires careful consideration when selecting peridynamic input parameters.

Keywords : Peridynamics; critical energy release rate; digital image correlation.

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