Numerical Study of Micro Hydro Deep Drawing

摘要

Micro hydro deep drawing (MHDD) is a budding micro sheet forming technology with enormous application potential.It draws increasing attention due to its superiorities over other micro manufacturing methods, such as the capacity to fabricate truly 3D products, the ability to handle metals and the high quality of products.However,tiny sizes of both products and tools result in difficulties in controlling and monitoring the drawing process.The hydraulic pressure, that significantly affects the formability and quality, varies with the change of fluid field constantly.Therefore, the hydraulic load can neither be simply treated as a constant load nor an initially assumed pressure distribution.Taking this into account, an Arbitrary Lagrangian Eulerian (ALE) model that considers fluid solid interaction (FSI) was developed in LS-DYNA to investigate the influence of hydraulic pressure on MHDD process and produced cups.The strong coupling behaviour between the fluid and solid phases can be examined in the simulation.Furthermore, a voronoi material model was additionally employed to consider the size effects of material properties.By comparison, a normal model that applies a constant pressure load was also developed.Simulation results indicate that the ALE model has more reasonable fluid distribution during the whole drawing process and higher accuracy than that of the normal model when comparing with experimental results.