Abstract: In this paper, based on the experimental studies of the surface and the internal damages during sheet forming process, a new forming limit prediction model has been presented by considering the effect of basic mechanical parameters, anisotropic parameter, initial thichness of the sheet, surface routhness parameters and internal damage parameters on the forming limit. The result shows that forming limit diagram calculated coincides with to experimental result very well.

Key words: 薄板, 成形, 极限, 损伤