Table 2.

Geometrical and mechanical parameters were estimated for each type of pipe tested.

Parameter	u.m.	PN10	PN16	PN25
β	-	0.86	0.78	0.70
ν	-	0.4	0.4	0.4
$E_1$	MPa	1.05 × 103	1.05 × 103	1.05 × 103
$E_2$ ${ⴄ}_2$	MPa	1.65 × 103	4.47 × 103	4.47 × 103
	MPa s	2.04 × 106	2.77 × 106	2.77 × 106
${ⴄ}_3$	MPa s	2.13 × 108	4.68 × 108	4.68 × 108
${\alpha }_{HDPE}$	µε/°C	200	200	200
$K_T$	-	4	4	4