Abstract
Near-threshold fatigue crack propagation tests were performed on circumferentially precracked round bars of medium carbon steel under mode III torsional loading. The crack propagation rate was decreased with crack extension because of the shear contact of the crack faces. The crack propagation rate without the influence of crack surface contact was determined by extrapolating the relationship between the crack propagation rate and the crack extension to the zero crack extension. The applied stress intensity factor range was divided into two parts : one was the effective value which was responsible for crack growth and the other was the shielding value. The resistance curve method was used to predict the fatigue limits for crack initiation and fracture. The R curve was constructed using the experimentally determined threshold value of the stress intensity range which was the sum of the threshold effective stress intensity range and the threshold shielding stress intensity range. The threshold effective stress intensity range was constant. The R curve was independent of the crack length and specimen dimensions. The predicted values agreed well with the experimental results.
Sign-in/Register to access full text options 
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 callMore From: TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series A
Disclaimer: 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.
