Hatami, F.; Varvani-Farahani, A. Local Ratcheting at the Notch Region of Non-Press-Fitted and Press-Fitted Al 7075-T6 Samples Undergoing Asymmetric Stress Cycles. Metals2023, 13, 1549.
Hatami, F.; Varvani-Farahani, A. Local Ratcheting at the Notch Region of Non-Press-Fitted and Press-Fitted Al 7075-T6 Samples Undergoing Asymmetric Stress Cycles. Metals 2023, 13, 1549.
Hatami, F.; Varvani-Farahani, A. Local Ratcheting at the Notch Region of Non-Press-Fitted and Press-Fitted Al 7075-T6 Samples Undergoing Asymmetric Stress Cycles. Metals2023, 13, 1549.
Hatami, F.; Varvani-Farahani, A. Local Ratcheting at the Notch Region of Non-Press-Fitted and Press-Fitted Al 7075-T6 Samples Undergoing Asymmetric Stress Cycles. Metals 2023, 13, 1549.
Abstract
The present study evaluates ratcheting response of notched and press-fitted Al 7075-T6 specimens under stress-controlled asymmetric cycles. The degree of interference fit (DIF) directly influenced progressive plastic strain magnitude and rate at notch root region. Local ratcheting at the hole-pin interference region was analyzed by means of two kinematic hardening rules of Ahmadzadeh-Varvani (A-V) and Chaboche coupled with the Neuber rule. Ratcheting strains at notch root of aluminum samples with DIF=0 (non-press-fitting samples) were measured to be highest in magnitude. For the press-fitted samples, however ratcheting strains dropped noticeably as DIF increased from 1% to 2%. Press-fitted samples plastically deformed the perimeter edge of notches and improved materials locally at the notch edge, resulting in a better resistance against ratcheting progress. Local ratcheting at different distances of 0.5, 1.3 and 3.0 mm from the notch root were evaluated for both pinned and unpinned samples through the hardening rules and compared with those of measured values. The predicted ratcheting curves by means of the A-V and Chaboche hardening rules closely agreed with experimental data and respectively positioned above and below the measured data.
Keywords
Local ratcheting; kinematic hardening model; backstress evolution; the Neuber rule; degree of interference fit (DIF); press-fitted and non-press-fitted samples
Subject
Engineering, Mechanical Engineering
Copyright:
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.
