An experimental study has been carried out to determine the effects of strain rate on mild steel under mainly cyclic loading. In addition, effects of loading history on the flow stress were also investigated. Tapered and notched round specimens of CAN/CSA G40.20/21 Grade 300W and ASTM A572 Grade 50 steels were tested under a variety of cyclic loading conditions at a strain rate ranging from 10<sup>-4</sup> s<sup>-1</sup> and 10<sup>-1</sup> s<sup>-1</sup>. A positive rate sensitivity on flow stress has been found for both these materials during initial cyclic loading. However, with continual loading, tests performed at the strain rates of 10<sup>-2</sup> and 10<sup>-1</sup> s<sup>-1</sup> show negative flow stress rate sensitivity due to adiabatic heating. The rupture strain decreases with strain rate for the strain rate range considered in this study. On the other hand, findings on the effect of strain rate on the fatigue life are inconclusive. The loading history effects on the stabilized cyclic stress-strain curve at a strain range are small if a sufficient number of loading cycles have been performed at that particular strain range.

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Conference Annual Conference of the Canadian Society for Civil Engineering 2013: Know-How - Savoir-Faire, CSCE 2013
Citation
Walker, A.T., & Khoo, H. A. (2013). An experiential study of the strain rate effects on mild steel for cyclic loading. Presented at the Annual Conference of the Canadian Society for Civil Engineering 2013: Know-How - Savoir-Faire, CSCE 2013.