Abstract
The Mode I and Mode II dynamic fracture toughness (DFT) values, KId and KIId for high strength steels 40Cr and 30CrMnSiNi2A were evaluated using a combined experimental-numerical method. The tests were performed on three point bend (3PB) and shear specimens with Hopkinson pressure bar. The time of crack initiation was determined by a strain gauge. With the assistance of 3-D transient finite element analysis, the temporal evolution of the dynamic stress intensity factor under different loading rates was obtained, and the DFT was determined by the fracture initiation time. In Mode I tests, a brittle transgranular fracture was found in 40Cr, while evidence for ductile fracture was observed on the failure surface of 30CrMnSiNi2A. In Mode II tests, both tensile cracks and adiabatic shear bands were found for the two steels. The effect of ligament size on fracture toughness was discussed. The correlations of KId and KIId with loading rate were also investigated. The micromechanisms of loading rate effect on the DFT were discussed for both modes.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
