Effect of Auto-Tuning on Serrated Flow Behavior
AbstractThe mechanical response of a servo-hydraulic testing system is affected by the stiffness of test specimens. An adaptive controller helps in auto-tuning the system by setting the optimal proportional-integral-derivative values for the subsequent test as the stiffness changes. This paper presents the effect of auto-tuning of various channels on the flow response of several commercial Al and Mg alloys and a mild steel. Strain-controlled monotonic tensile tests were performed at a given strain rate of 1 × 10−4 s−1 after auto-tuning of position, load, and strain channels in different combinations. Serrated flow or Portevin–Le Chatelier effect was observed in the Al alloys after auto-tuning of either position channel only or position and load channels. However, the serrations of Al alloys were shielded after further auto-tuning of strain channel. The stress-strain curves of Mg alloys and mild steel were observed to be basically free of serrations under any combinations of auto-tuning, which confirms that the serrated flow is a property of specific materials rather than a machine system noise. View Full-Text
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Mohammed, S.; Chen, D. Effect of Auto-Tuning on Serrated Flow Behavior. Metals 2019, 9, 845.
Mohammed S, Chen D. Effect of Auto-Tuning on Serrated Flow Behavior. Metals. 2019; 9(8):845.Chicago/Turabian Style
Mohammed, S.M.A.K.; Chen, D.L. 2019. "Effect of Auto-Tuning on Serrated Flow Behavior." Metals 9, no. 8: 845.
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