Constraint modified time dependent failure assessment diagram (TDFAD) based on C(t)-A2(t) theory for creep crack

Yanwei Dai, Yinghua Liu, Fei Qin, Yuh J. Chao, Haofeng Chen

Research output: Contribution to journalArticle


Due to the potential influence of constraint effect on failure assessment, a link is needed to bridge the constraint effect characterized by higher order term asymptotic solution and time dependent failure assessment diagram (TDFAD). In this paper, a modification method for creep toughness incorporating C(t)-A2(t) theory is proposed based on Nikbin-Smith-Webster model. The relation between Q-term and A2(t)-term is also presented for creep crack. Results show that the creep toughness can be influenced by constraint parameter remarkably. A modified TDFAD is proposed based on C(t)-A2(t) solution. Based on the creep data of 316H stainless steel and various compact tension specimens, the modified TDFAD curves considering constraint effect characterized with A2(t)-term is presented and discussed, which indicates the important role of constraint effect on the assessment boundary of TDFAD. The research given in this paper can provide an alternative method in which the constraint effect can be included in TDFAD under high temperature.
Original languageEnglish
Article number105193
Number of pages9
JournalInternational Journal of Mechanical Sciences
Early online date25 Sep 2019
Publication statusPublished - 1 Jan 2020



  • creep toughness
  • constraint effect
  • A2 -parameter
  • CT specimen

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