Journal
JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH
Volume 180, Issue -, Pages -Publisher
ELSEVIER SCI LTD
DOI: 10.1016/j.jcsr.2021.106571
Keywords
Bridge steel Q345qD; Fatigue crack initiation; Strain-controlled fatigue; Energy approach; Low temperature
Funding
- National Natural Science Foundation of China [51908501, 51678339]
Ask authors/readers for more resources
This study investigates the resistance to fatigue crack initiation of Q345qD steel and the effect of low temperatures on its fatigue life, demonstrating an increased resistance and excellent fatigue performance of Q345qD steel under low temperatures. The study proposes the use of plastic strain energy density and fatigue toughness concepts for predicting the fatigue life of Q345qD steel at room and low temperatures.
The lack of in-depth understanding on the low-temperature fatigue cracking performance has limited the extensive application of the Q345qD bridge steel in cold and severely cold regions. This study investigates the resistance to the fatigue crack initiation of the Q345qD steel through a series of strain-controlled fatigue tests of smooth coupons at room and low temperatures. Experimental results present the cyclic stress-strain relationship, non-Masing properties and Coffin-Manson-type fatigue crack initiation resistance. Thereafter, this study analyzes the effect of low temperatures on the stain-controlled fatigue life of the studied Q345qD steel using the different energy approaches. Results indicate that the low temperatures within-60 ?C increase the resistance to the fatigue crack initiation and the cyclic strain-hardening coefficients. A comparison with other structural steels demonstrates the excellent fatigue performance of the Q345qD steel at room and low temperatures. Since the corresponding stress amplitudes of the Q345qD steel under each cyclic strain range exhibit some strain-range-dependent cyclic softening/hardening behavior, the plastic strain energy density and the concept of fatigue toughness are more suitable and effective to predict the fatigue life of the Q345qD steel at room and low temperatures. Finally, a simple and accurate method for calculating the plastic strain energy density has been proposed. ? 2021 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available