In hydroforming of hollow metal articles in a die, such as
pressure-ram-forming procedures, a method of decreasing cycle time of the
forming process, while ensuring acceptable product properties and
avoiding failures, by modeling the process using finite element analysis
to establish a pressure-time history that optimizes the forming operation
and applies failure limits to selected variables such as minimum wall
thickness or maximum strain rate, and transferring this pressure-time
history to a computer controlling the forming process. Thermocouple
and/or continuity sensors are incorporated into the die wall and
connected to the computer so as to provide active feedback from the die
to the control of the process.