Abstract
CNC press-brake forming is widely used to transform sheet-metal blanks into complex three-dimensional shapes in a low quantity high variety manufacturing environment. Sheet-metal bend sequence planning is a complex combinatorial problem. Process planning and tolerance reasoning for sheet-metal forming are critical to reduce manufacturing time and to address accuracy aspects. Handling time and accuracy of sheet-metal-formed components strongly depend upon the bending sequence. Process and material variations shrink the tolerance zones and therefore their effect must be incorporated in the overall sheet-metal process planning activity. Monte Carlo simulations are used in this article to evaluate the effect of process and material variations on bending accuracy. Branch-and-bound, traveling salesman problem (TSP)-based techniques are used to identify potential feasible bending sequences. Results from the Monte Carlo simulations are used as input for sheet-metal bend sequence planning. In the case study, proposed methodology is used for available industrial sheet-metal components. Resulted tolerance zones attenuated after the probabilistic deflection analysis. Expected error input from probabilistic deflection analysis produced bending sequences which resulted in formed components within designed accuracy limits. Possibility of forming out of tolerance components is also attenuated.