Investigation on True Stress-Strain Curves of Flat and Corner Regions of Cold-Formed Section Using 3D Digital Image Correlation Method

Table 2

Mechanical parameters of engineering and true stress-strain curves of flat coupons.

Types of curves	Specimens	(MPa)		(MPa)		(MPa)
Engineering stress-strain curves	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
True stress-strain curves	TW-1	262.033	0.0012	554.07	0.332	—	—
	TW-2	255.463	0.0011	548.14	0.324	—	—
	TW-3	262.68	0.0011	542.26	0.323	—	—
	BW-1	255.13	0.0012	570.56	0.354	—	—
	BW-2	266.04	0.0012	576.83	0.331	—	—
	BW-3	262.63	0.0011	553.42	0.308	—	—
Average values of engineering curves		257.33	0.0013	411.79	0.249	316.32	0.467
Average values of true curves		260.66	0.0012	557.55	0.329	—	—
Improvements of average values		1.29%	−7.69%	35.40%	32.13%	—	—