The industrial transport industry is constantly trying to reduce the mass of structural components. In order to do this, many components become multifunctional and their geometries become very complex. When manufacturing these components, engineers use various optimization strategies, incorporating numerical modeling methods, in order to take into account the design and manufacture steps. However, the simulation can be very time consuming. This work focus on the improvement of the numerical simulation of sheet metal forming processes for deep drawn components. firstly, numerical methods have been developed to reduce the CPU time for the simulation of incremental sheet forming. A dynamic explicit scheme is use in which the velocity of the tool is varied. This method permits significant reduction of the CPU time, while maintaining good accuracy of the geometry and thickness. This work has also focused on the use of incremental deformation theory to reduce the calculation time for elasto-plastic analyses. Accuracy is maintained however a time gain of only 4.5% is achieved. In addition, a simplified approach has been developed to model the contact between the tool and the sheet. Good accuracy is observed with a reduction of the CPU by a factor of 2.13 compared with the variable tool velocity approach. Secondly, a study of the manufacturing of deep drawn parts by superplastic forming has been undertaken. This is because in the future it is expected that both of these processes will be used to form one part, in sequential operations. The aim was to determine an optimal pressure law by numerical simulation. Two algorithms have been developed. The appropriate algorithm to use depends on the type of forming machine available. The superplastic domain is well controlled with the algorithms developed. A reduction of the CPU time by a factor of 3 is observed in comparison with other algorithms found in the literature.
Keywords:
finites elements; elasto-plasticity; contact; pressure law; incremental sheet forming; superplasticity