Design of Hydraulic Bulging Die for Automobile Torsion Beam and Optimization of Forming Process Parameters

Table 2

Level factor setting table.

Level	Factor
	A	B	C	D
	Supporting pressure (MPa)	Molding pressure (MPa)	Feeding quality (mm)	Friction coefficient
1	20	150	25	0.075
2	40	180	30	0.1
3	60	210	35	0.125
4	80	240	40	0.15