Investigation on True Stress-Strain Curves of Flat and Corner Regions of Cold-Formed Section Using 3D Digital Image Correlation Method
Table 1
Mechanical parameters of engineering stress-strain curves.
Types of coupons
Specimens
(MPa)
(MPa)
(MPa)
Flat coupons
TW-1
260.64
0.0013
410.77
0.244
309.76
0.468
TW-2
254.26
0.0012
406.66
0.264
323.79
0.457
TW-3
247.88
0.0012
402.55
0.232
313.507
0.455
BW-1
253.58
0.0013
410.42
0.264
304.76
0.509
BW-2
265.67
0.0013
426.44
0.243
322.272
0.467
BW-3
261.97
0.0012
413.91
0.244
323.81
0.447
Corner coupons
TB-1
410.62
0.002
437.99
0.013
357.15
0.109
TB-2
383.75
0.002
441.94
0.018
338.52
0.136
TB-3
370.78
0.002
441.35
0.02
343.64
0.125
BB-1
380.78
0.002
440.13
0.023
366.35
0.109
BB-2
380.78
0.002
443.23
0.024
377.68
0.109
BB-3
395.22
0.002
443.44
0.013
373.94
0.107
Average values of flat coupons
257.33
0.0013
411.79
0.249
316.32
0.467
Average values of corner coupons
386.99
0.002
441.35
0.0185
359.55
0.116
Improvements of average values
50.38%
53.85%
7.18%
ā92.57%
13.67%
ā75.16%
Note. (1) is the yielding strength; (2) is the yielding strain; (3) is the ultimate strength; (4) is the corresponding ultimate strain; (5) is the fracture stress; and (6) is the fracture strain.
