PSI - Issue 39

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Abhishek Tiwari / Procedia Structural Integrity 39 (2022) 290–300 Author name / Structural Integr ty P o edi 00 (2019) 000–000

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Fig. 7. Influence on the crack driving force as the crack tip approaches the interface in a plastic to creeping material transition.

As the J behaviour with time is linear incremental, the creeping material (Material 2) will become more and more compliant with time. This feature of plastic to creep transition can be used to increase the fracture resistance of the material because of the fact that as CDF decreases, more force (loading parameter) will be required for the crack to extend. 6. Conclusions In this work, transition of crack between two differently creeping material and between elastic plastic and elastic power law creep material is studied numerically using finite element method on half symmetric CT specimen in two dimensions. The effect of such transitions are studied using material constitutive relation independent configurational force concept. The results show that between two differently creeping material the stiff to compliant transition of crack is similar to that in the elastic plastic material, previously investigated by various researchers. On the other hand, the elastic plastic to elastic power law creep transition of crack shows a unique behaviour of trend reversal at the location of the crack closest to the interface. It is also brought out that under elastic+plastic to Elastic +creep material transition C t or C * type of integrals are not describing the complete behavior as plastic strains are excluded in their calculation. On the other hand, dJ/dt represents a better picture of the crack as it includes elastic, plastic as well as creep strains and strain energy densities in its calculation. 4. Online license transfer All authors are required to complete the Procedia exclusive license transfer agreement before the article can be published, which they can do online. This transfer agreement enables Elsevier to protect the copyrighted material for the authors, but does not relinquish the authors’ proprietary rights. The copyright transfer covers the exclusive rights to reproduce and distribute the article, including reprints, photographic reproductions, microfilm or any other reproductions of similar nature and translations. Authors are responsible for obtaining from the copyright holder, the permission to reproduce any figures for which copyright exists. Acknowledgements The author expresses his gratitude to the Indian Institute of Technology Ropar, Punjab and the Institute Seed Grant (ISIRD Phase 1).