Experimental and Theoretical Assessment of Mode II Fracture Toughness for Cracked Ductile Specimens with High Strain-Hardening

Document Type : Research Article

Authors

1 IUST

2 Faculty of New Science and Technologies, University of Tehran

Abstract

In this research, the mode II fracture toughness of O-notched diagonally loaded square plate samples with pre-existing cracks which are made of stainless steel 316L with specifications of highly ductile behavior and great strain hardening is investigated theoretically and experimentally. For this purpose, several fracture tests are carried out on the pre-cracked specimens to determine the fracture toughness experimentally. The experimental observations and the load-displacement curves obtained from the fracture tests illustrate that the pre-cracked specimens undergo large plastic deformations at the onset of crack propagation. Afterward, the fictitious material concept is used to estimate the values of fracture toughness achieved experimentally. By using the fictitious material concept, the fracture toughness of pre-cracked specimens fabricated from stainless steel 316L could be estimated without the need for complicated and time-consuming elastic-plastic failure analysis and by performing only linear elastic analysis. For this purpose, the fictitious material concept is simply combined with mean stress, generalized mean stress, maximum tangential stress, generalized maximum tangential stress, strain energy density, and generalized strain energy density criteria. It is shown that the combination of fictitious material concepts with four linear elastic brittle fracture criteria is quite successful in predicting the mode II fracture toughness of ductile pre-cracked specimens. 

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References

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Amirkabir Journal of Mechanical Engineering
Volume 53, Issue 10
January 2022
Pages 5141-5158

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