Patent ID: 11907624
Assignee: TIANJIN UNIVERSITY
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 3:
4. The method for characterizing the propagation of the metallic short cracks and long cracks according to claim 3, further comprising:
in the process of acquiring the crack tip opening displacement amount according to a Zheng-Hirt crack tip blunting model, taking a blunting crack tip as a micro-notch, and acquiring the material critical fracture stress according to a metallic notch cracking criterion, wherein an expression of the material critical fracture stress is:

Ktσmax=√{square root over (Eσfεf)}=σff 

in the expression, Kt is a theoretical stress concentration coefficient, σf and εf are respectively a true fracture stress and fracture ductility that are related to material section shrinkage, and σff represents the material critical fracture stress.