ISSN:
1662-8985
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
The Mode I and Mode II dynamic fracture toughness (DFT) values, KId and KIId for highstrength steels 40Cr and 30CrMnSiNi2A were evaluated using a combined experimental-numericalmethod. The tests were performed on three point bend (3PB) and shear specimens with Hopkinsonpressure bar. The time of crack initiation was determined by a strain gauge. With the assistance of3-D transient finite element analysis, the temporal evolution of the dynamic stress intensity factorunder different loading rates was obtained, and the DFT was determined by the fracture initiationtime. In Mode I tests, a brittle transgranular fracture was found in 40Cr, while evidence for ductilefracture was observed on the failure surface of 30CrMnSiNi2A. In Mode II tests, both tensile cracksand adiabatic shear bands were found for the two steels. The effect of ligament size on fracturetoughness 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
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/40/transtech_doi~10.4028%252Fwww.scientific.net%252FAMR.33-37.351.pdf
