Table 1.

Volume fractions ${\phi }^i$, time constants $T^i$ and $L_2$-errors for the best fit of Eq. (1) to experimental data shown in Fig. 8

		Uniaxial	Strip-biaxial		Equi-biaxial
		x	x	y	x	y
Negative change in load	${\phi }^1$	0.58	0.41	0.34	0.46	0.48
	${\phi }^2$	0.42	0.59	0.66	0.54	0.52
	$T^1\hspace{0.17em}$(h)	0.19	0.18	0.08	0.23	0.24
	$T^2$ (h)	14.11	13.00	5.95	11.41	7.12
	$L_2$-error (%)	14.86	9.44	26.30	8.62	8.04
Positive change in load	${\phi }^1$	0.54	0.67	0.53	0.70	0.64
	${\phi }^2$	0.46	0.33	0.47	0.30	0.36
	$T^1$ (h)	0.11	0.00	0.00	0.36	0.31
	$T^2$ (h)	7.18	4.2 × ${10}^{15}$	2.5 × ${10}^4$	14.98	22.60
	$L_2$-error (%)	18.60	14.80	40.31	12.83	10.90