Table 3.

The total strain energy per unit volume (W) and the degree of nonlinearity (DNL) of canine aorta calculated according to the material constants given in Table 1

Circumf. stretch ratio	λθθ	1.0	1.2	1.4	1.6	1.8
Circumf. strain	Eθθ	0.0	0.22	0.48	0.78	1.12
Strain energy per unit volume, W
Long. stretch ratio	λzz = 1.0	0.000	0.906	4.296	12.441	29.085
	λzz = 1.2	0.962	2.408	6.659	15.680	33.920
	λzz = 1.3	2.495	4.279	9.070	19.000	39.000
	λzz = 1.4	5.268	7.454	12.980	24.290	47.210
Degree of nonlinearity, %
Long. stretch ratio	λzz = 1.0	0.00	0.66	3.27	8.99	19.74
	λzz = 1.2	3.46	2.87	5.16	10.34	20.79
	λzz = 1.3	8.44	6.89	8.32	13.47	23.85
	λzz = 1.4	16.06	13.68	14.24	18.97	29.20

DNL = 100 × nonlinear strain energy/total strain energy.