Table of Contents Author Guidelines Submit a Manuscript
Advances in Civil Engineering
Volume 2017, Article ID 6272906, 7 pages
https://doi.org/10.1155/2017/6272906
Research Article

Research on Fatigue Strain and Fatigue Modulus of Concrete

1College of Civil Engineering, Chongqing Three Gorges University, No. 666 TianXing Road, Wanzhou District, Chongqing 404100, China
2Engineering Research Center of Bridge Structure and Material in the Mountainous Area, Chongqing Jiaotong University, No. 66 XueFu Road, Nan’an District, Chongqing 400074, China

Correspondence should be addressed to Jianting Zhou; moc.361@uohz-tj

Received 27 March 2017; Accepted 14 June 2017; Published 12 July 2017

Academic Editor: Pier Paolo Rossi

Copyright © 2017 Fangping Liu and Jianting Zhou. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Concrete fatigue strain and fatigue modulus evolution play a vital role in the evaluation of the material properties. In this paper, by analyzing the advantages and disadvantages of existing concrete strain analysis methods, the level-S nonlinear fatigue strain model was proposed. The parameters’ physical meaning, the ranges, and the impact on the shape of the curve were all discussed. Then, the evolution model of fatigue modulus was established based on the fatigue strain evolution model and the hypothesis of fatigue modulus inversely related fatigue strain amplitude. The results indicate that the level-S model covered all types of fatigue strain evolution. It is very suitable for the description of strain evolution of concrete for its strong adaptability and high accuracy. It was found that the fitting curves coincided with the experimental curves very well, and the correlation coefficients were all above 0.98. The evolution curves of fatigue strain modulus both have three stages, namely, variation phase, linear change stage, and convergence stage. The difference is that the fatigue strain evolution curve is from the lower left corner to the upper right corner, but the fatigue modulus evolution curve is from the upper left corner to the right lower corner.