Abstract: A new concept, essential technical design (ETD) for automobile stretching part which provides succeeding FEM simulation with initial conditions, its necessity and characteristics are presented. It is pointed out that length of flown-in material (LFM), which flows into female die from underside of blank-holder during forming, is an external index of local forming resistance. Local LFM can be got from the height of automobile panel wall with ANNs. The shape of blank can be obtained by adding the local LFM to the shape of stretching part, which is got by adding excess material to finial automobile panel; Moreover, by converting design principles to restrictions, genetic algorithm (GA) and ANN are applied to optimize the geometric parameters of drawbead and die corner. The application of feature modeling and object oriented knowledge base is also discussed.

Key words: ANNGA, Automobile panel, Expert system, Stretching forming