Patent ID: 6915244

Claim:
A method for predicting an amount of dimensional accuracy defect at the time of performing a press-forming of a metal sheet comprising: setting a stress-strain relationship with respect to said metal sheet based on an elastic-perfectly plastic solid material model having a constant stress value after being yielded; formulating a first prediction equation of an amount of dimensional accuracy defect using said stress-strain relationship based on said elastic-perfectly plastic solid material model; setting a value which is equal to or below a tensile strength and exceeds a yield strength as an apparent yield strength with respect to said metal sheet; formulating a second prediction equation of an amount of dimensional accuracy defect which considers work hardening by replacing a portion of said first prediction equation of an amount of dimensional accuracy defect corresponding to said yield strength with said apparent yield strength; and obtaining a dimensional accuracy defect amount using said second prediction equation of an amount of dimensional accuracy defect which considers work hardening.