Fig. 11. Calibration results. (a) Calibration: εmand εm45. (b) Calibration: εmrr.
Table 4
Tests summary.
Test Strip speed
(m/min)
Rotation speed ω
(rad/s)
Rolling force FR
(N/mm)
1 25 2.13 6220
2 50 4.26 6430
3 100 8.53 6660
4 300 25.58 7050
5 400 34.00 7200
rolling conditions, even though this paper focuses on isothermalinterpretation. Further investigations have to focus on hot rollingconditions with thermal compensation, and an inverse methodusing a thermo-elastic coupling as developed by Weisz-Patraultet al. (2013a).5.1. Influence of rolling speedsVarious rotation speeds are tested under similar cold rollingconditions. Rolling parameters are listed in Table 5, and testsare summarized in Table 4. Rotation speeds are set from veryslow experimental conditions (strip speed: 25 m/min) to semi-industrial conditions (strip speed: 400 m/min). Rolling forces are
Table 5
Rolling parameters.
f (Hz) 3378 Data acquisition frequency
t0 (mm) 2.8 Strip entry thickness
t1 (mm) 2.154 Strip exit thickness
T (%) 30 Thickness reduction ratio
T
0 (MPa) 39.4 Strip entry tension
T
1 (MPa) 117.5 Strip exit tension
lC (mm)
14 Contact length
relatively similar (from 6220 N/mm to 7200 N/mm). These testsaim at demonstrating the applicability of the inverse method withthe detailed experimental apparatus in high speed industrial con-ditions, with rotation speeds around 70 rad/s corresponding to800 m/min strip speed. Therefore, data acquisition frequency is akey point for relevant measurement interpretation. In this sectionthe data acquisition system with the higher frequency f = 3378 Hzis used.Measured strains for four cycles are presented in the contactvicinity for tests 1 and 5 in Fig. 12. Reproducibility is excellent fromone cycle to another (similar figures are obtained for tests 2–4).Detailed measured signals in the contact vicinity are presented inFig. 13 for the first cycle. Of course the number of measurementFig